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| Term | Definition/Description | Source |
| sag correction | (taping) The difference between the effective length of a tape, or part of a tape, when supported continuously throughout its length and when supported at a limited number of independent points. Base tapes usually are used with three or five points of support, and hang in curves (catenaries) between adjacent supports. Correction for sag is not required when the method of support in use is the same as was used in the standardization of the tape; only the standardization correction is applied. A base tape may also be used supported throughout or with four points of support, as on a railway rail. Also called catenary correction. | HDBK-850 |
| sailing chart | A small-scale chart used for offshore sailing between distant coastal ports and for plotting the navigator's position out of sight of land and as he approaches the coast from the open ocean. They show offshore soundings and the most important lights, outer buoys, and natural landmarks which are visible at considerable distances. | HDBK-850 |
| Sailing Directions | A descriptive book for the use of mariners, containing detailed information of coastal waters, harbor facilities, etc. Also called coast pilot; pilot. | HDBK-850 |
| sample | An example taken from a dataset being representative for the whole dataset. | CEN/TC 287 |
| sample | A set of observations, used to determine the most probable value of a particular parameter, and/or used to estimate the accuracies of the observations and/ or accuracy of the parameter. | HDBK-850 |
| sample variance | True variance can only be computed from some sample. The term sample variance is used when wishing to make reference to a computed variance from a specific sample, as opposed to an assumed or previously estimated variance of some particular class of observations or parameters. In general, if the sample variance of some class of observations in a weighted least square adjustment differs too greatly from the assumed variance used for weighing the observations, the adjustment should be repeated with refined weights based on the sample variance. See variance. | HDBK-850 |
| Sandia National Laboratories | Sandia is a national security laboratory operated for the United States Department of Energy (DoE) by the Sandia Corporation, a Lockheed-Martin Co. Sandia works in partnership with universities and industry to enhance the security, prosperity, and well-being of the nation. Sandia provides scientific and engineering solutions to meet national needs in nuclear weapons and related defense systems, energy security, and environmental integrity, and to address emerging national challenges for both government and industry. Sandia designs all non-nuclear components for the nation's nuclear weapons, performs a wide variety of energy research and development projects, and works on assignments that respond to national security threats - both military and economic. Sandia National Laboratories' main site is in Albuquerque, NM, with an additional laboratory in Livermore, CA. | Sandia Web Site |
| sanitization | The process of editing or otherwise altering intelligence information or reports to protect sensitive intelligence sources, methods, capabilities, analytical procedures , or privileged information in order to permit wider dissemination of the data. | USIS 95 |
| Sanson-Flamsteed map projection | See sinusoidal map projection. | HDBK-850 |
| saros | The eclipse cycle of about 18 years, almost the same length as 223 synodical months. At the end of each saros, the Sun, Moon, and line of nodes return to approximately the same relative positions and another series of eclipses begins, closely resembling the series just completed. See also lunar cycle. | HDBK-850 |
| satellite | An attendant body, natural or man-made, that revolves about another body, the primary. See also active satellite; communications satellite; Earth satellite; equatorial satellite; geodetic satellite; lunar satellite; NAVSTAR Global Positioning System; Navy Navigation Satellite System; passive satellite; polar satellite; synchronous satellite. | HDBK-850 |
| satellite access | When the relative geometry between a satellite and a ground point is within the defined access viewing constraints. | USIS 95 |
| satellite geodesy | The discipline which employs observations of an Earth satellite to extract geodetic information. | HDBK-850 |
| Satellite Geophysics Programs | [NIMA] programs that provide for the operation and maintenance of fixed and mobile satellite tracking systems and the processing of data from geodetic satellites. The data collected by these stations are used in geoid profiles, precise satellite ephemerides, geodetic point positions and related products. | HDBK-850 |
| Satellite pour l'Observation de la Terre (SPOT) | The SPOT satellite Earth Observation System was designed by the Centre National d'Etudes Spatiales (CNES), France, and developed with the participation of Sweden and Belgium. The system comprises a series of spacecrafts plus ground facilities for satellite control and programming, image production and distribution. SPOT 1 was launched on 22 February 1986, and withdrawn from active service on 31 December 1990. SPOT 2 was launched on 22 January 1990 and is still operational. SPOT 3 was launched on 26 September 1993. An incident occured on SPOT 3 on November 14, 1997. After 3 years in orbit the satellite has stopped fonctioning. SPOT 4 was successfully launched on 24 March 1998 and began imaging on 27 March 1998. The Spot 4 satellite has been designed to provide even higher performance than its predecessors. Its most significant new features are an additional band in the short-wave infrared (SWIR) and an instrument dedicated to studying vegetation. Engineering work for SPOT 5 has began so that the satellite can be launched late in 2002. | SPOTIMAGE Web Site |
| Satellite Reconnaissance Advance Notice | Provides advanced warning of reconnaissance satellite orbits so military commanders can take appropriate action. | USIS 95 |
| satellite surveying | 1. (Doppler) The process of positioning one or more points on the Earth's surface by collecting Doppler shift data from passes of Navy navigation satellites. See also point positioning; short arc; translocation. 2. (NAVSTAR) The position (by resection) of a point receiving signals from four satellites of the Global Positioning System. | HDBK-850 |
| satellite trail | A streak like image of a satellite recorded on a stellar plate by a photographic time exposure. | HDBK-850 |
| satellite triangulation | The determination of the angular relationships between two or more stations by the simultaneous observation of an Earth satellite from these stations. | HDBK-850 |
| satellite triangulation stations | Triangulation stations whose angular positions relative to one another are determined by the simultaneous observation of an Earth satellite from two or more of them. | HDBK-850 |
| saturable reactor | See flux-gate magnetometer. | HDBK-850 |
| S-band High Precision Short-range Electronic Navigation (SHIRAN) | An electronic distance-measuring system for measuring distances with geodetic accuracy from an airborne station to each of four ground stations. | HDBK-850 |
| scalability {DII COE} | The ability of a system to increase (decrease) functionality , the amount of data which can be processed or stored, and responsiveness without the need to re-write applications through the addition (removal) of hardware and software components. Scalability is critical in achieving "NCA to foxhole" at reasonable cost. | DII COE IRTS |
| scalability | The ability to use the same application software on many different classes of hardware/software platforms from personal computers to super computers (extends the portability concept). [USAICII] The capability to grow to accommodate increased work loads. | DISA CFS |
| scalability | The ability to provide functionality up and down a graduated series of application platforms that differ in speed and capacity. | IEEE P1003.0 |
| scalability | 1. The capability to adapt hardware or software to accommodate changing work loads. [OS-JTF] 2. The ability to use the same application software on many different classes of hardware/software platforms from personal computers to super computers (extends the portability concept). The ability to grow to accommodate increased work loads. [TAFIM, Version 3.0, Vol. 1 and 3] | JTA 2.0 |
| scalability | The ability to change the component configuration of a system to fit desired application contexts. | OpenGIS Guide |
| scalar | Any physical quantity whose field can be described by a single numerical value at each point in space. A scalar quantity is distinguished from a vector quantity by the fact that a scalar quantity possesses only magnitude, whereas a vector quantity possesses both magnitude and direction. | HDBK-850 |
| scale | 1. (JCS) The ratio or fraction between the distance on a map, chart, or photograph and the corresponding distance on the surface of the Earth. 2. A series of marks or graduations at definite intervals on a measuring device or instrument. 3. Measurement by means of a scale. See also compilation scale; conversion scale; equivalent scale; graphic scale; Invar scale; model scale; photographic scale; plotting scale; principle scale; representative fraction; reproduction scale; scaling; x-scale; y-scale; z-scale. | HDBK-850 |
| scale checking | 1. The process of determining the scale of an aerial photograph, or more correctly, the altitude above sea level which best fits the print. 2. (stereocompilation) The process of determining the scale of a vertical photograph for points at a specific elevation and the subsequent measurement of direction and distance therefrom. | HDBK-850 |
| scale error | A systematic error in the lengths of survey lines usually proportional to the lengths of the lines. See also instrument error. | HDBK-850 |
| scale factor | A multiplier for reducing a distance obtained from a map by computation or scaling to the actual distance on the datum of the map. Also, in the state coordinate systems, scale factors are applied to geodetic lengths to obtain grid lengths, or to grid lengths to obtain geodetic lengths. Both are lengths on a sea level datum, but the grid lengths are affected by the scale change of the map projection. | HDBK-850 |
| scale indicator | A logarithmic scale devised as a rapid and convenient method of determining the natural scale of a map from the divisions marked on the graphic scales, or from the intervals of latitude on a map. | HDBK-850 |
| scale of reproduction | The enlargement or reduction ratio of an original to the final copy. This ratio is expressed as a diameter, percent, times (X), or a fraction. Also called enlargement factor; reduction factor; reproduction ratio. See also contact size; diameter enlargement; make line; percent of enlargement/reduction; times (X) enlargement. | HDBK-850 |
| scale-ratio mosaic | An assembly of photographic prints brought to a common scale by projection printing to scale factors obtained from map distances to allow the best possible fit of contiguous photo detail. | HDBK-850 |
| scaling | 1. Alteration of the scale in photogrammetric triangulation to bring the model into agreement with a plot of horizontal control. 2. Fitting a stereoscopic model to a horizontal control plot. A step in absolute orientation. Also called scaling the model. 3. Determining the scale of a photograph or graphic. 4. (cartography) See cartometric scaling. | HDBK-850 |
| scaling the model | See scaling, definition 2. | HDBK-850 |
| scan lines | Successive parallel strips of captured data from a sensor, such as a row of a raster grid, to be printed on a single line of a raster display device; or recorded in a single sweep of the mirror of an optical scanner system, or radar scanning system; or a single addressing of the linear array detector of a pushbroom scanner. | HDBK-850 |
| scan positional distortion | In a panoramic camera system, the displacement of images of ground points from their expected cylindrical positions caused by the forward motion of the vehicle as the lens scans. | HDBK-850 |
| scanner | 1. A device for automatically converting images from maps and photographs, or from part of the real world into digital form. 2. Any device that systematically decomposes a sensed image or scene into pixels and then records some attribute of each pixel. | HDBK-850 |
| scatterometry | A method of using radar to measure the variation of radar scattering coefficients. These variations may be used by geoscientists to discriminate between surfaces with different roughness and materials. The scatterometer is distinguished from other radars by its ability to measure amplitude. | HDBK-850 |
| scene generation | A two-dimensional display with underlaying terrain data portrayed to appear as if three-dimensional. Normally, an image consists of an oblique view with perspective. | HDBK-850 |
| scene matching area correlator (SMAC) | An electrooptical correlation system which uses photographic reference material matched with onboard realtime scenes to achieve correlation. The reference scene is prepared from reconnaissance photographs and is stored in the form of a photographic transparency. The reference is placed around the inner circumference of a drum that rotates at a high angular velocity. The reference then forms a continuous strip which modulates or chops the projected image being focused on it by the optical system. The realtime energy from the ground within the field-of-view is spatially modulated by the transmissivity of the reference transparency. | HDBK-850 |
| scene temperature | The average temperature of a given area on the Earth's surface (within the image scene) at any instant of time. | USIS 95 |
| Scheimpflug condition | The requirement that object, lens, and image planes intersect in a common line for sharp focus in any direct projection system. | HDBK-850 |
| schema | A description of the logical structure of a database. See also: data model. [IEEE 610.5] | IEEE 610-1990 |
| schema | A description of a feature's attributes, or more specifically, the specific attribution model for a feature in terms of primitive data types and constraints on these types. | OpenGIS Guide |
| Schott base-line measuring apparatus | A contact, compensating base-line measuring apparatus composed of three parallel bars; the middle bar of zinc, the outer bars of steel. One end of each steel bar is free; the other end is fastened to an end of the zinc bar, a different end for each steel bar. The lengths of the bars are so proportioned with respect to their coefficients of thermal expansion that a constant distance is maintained between the free ends of the steel bars. | HDBK-850 |
| scientific and technical (S&T) intelligence (S&TI) | Scientific and technical (S&T) intelligence (S&TI) is concerned with the analysis of foreign technology, i.e., research and development activities and potential and current capabilities of weapons systems. | USIS 95 |
| scintillation | See shimmer. | HDBK-850 |
| scissors inversor | See Peaucellier inversor. | HDBK-850 |
| screen | See area pattern screen; biangle screen; dot screen; halftone screen; magenta contact screen. | HDBK-850 |
| screen angle | (photography) The angle which the rows of halftone dots make with the vertical when right-reading. The angle is measured clockwise with 0° at 12 o'clock. | HDBK-850 |
| screening | See masking. | HDBK-850 |
| scribed plate | See scribed sheet. | HDBK-850 |
| scribed sheet | A scribing surface on which the reproduction scribing has been completed. Also called scribed plate. | HDBK-850 |
| scriber | An instrument holding a scribing point; used for scribing on coated plastics. Also called engraver; graver; scribing instrument. See also engraver rectagraver; rigid tripod engraver; straight line graver; subdivider; swivel graver; turret graver. | HDBK-850 |
| scribing | (JCS) A method of preparing a map or chart by cutting the lines into a prepared coating. [The process of preparing a negative which can be reproduced by contact exposure. Portions of a photographically opaque coating are removed from a transparent base with specially designed tools.] Also called negative scribing. | HDBK-850 |
| scribing guide | See guide. | HDBK-850 |
| scribing instrument | See scriber. | HDBK-850 |
| scribing points | Needles or blades in various diameters or cross-section shapes ground and sharpened to prescribed dimensions. Used in scribers for scribing on coated plastics. | HDBK-850 |
| script | A file containing commands to be executed by an operating system shell. Such files are generally called "scripts" in the UNIX environment, but are typically called "batch files" in the MS-DOS and Windows environment. | DII COE IRTS |
| sea level | The height of the surface of the sea at any time. See also ideal sea level; mean sea level. | HDBK-850 |
| sea level contour | A contour line delineating points at sea level. | HDBK-850 |
| sea level datum | See mean sea level. | HDBK-850 |
| sea level datum of 1929 | See National Geodetic Vertical datum of 1929. | HDBK-850 |
| sea level variation | Sea level varies from day to day, from month to month, and from year to year. This variation is attributed to meteorological conditions and should not be confused with the lunar tides. | HDBK-850 |
| seamless data base | A data base structured without segmentation or tiling, thereby eliminating the need to begin and terminate chains at boundaries and have topological pointers reference tiles as well as other entities. The result is a data base physically smaller than a tiled one but one in which search times can be quite long. | HDBK-850 |
| seamless interface | Ability of facilities to call one another or exchange data with one another in a direct manner. Integration of the user interface that allows a user to access one facility through another without any noticeable change in user interface conventions. [DSAC SYS IM] | DISA CFS |
| search and rescue chart | A chart designed primarily for directing and conducting search and rescue operations. | HDBK-850 |
| SECAM | French standard for analog video format. | Multimedia |
| secant | 1. A line that cuts a geometric curve or surface at two or more points. 2. A trigonometric function of an angle. See also secant method. | HDBK-850 |
| secant conic chart | See conic chart with two standard parallels. | HDBK-850 |
| secant conic map projection | See conic map projection with two standard parallels. | HDBK-850 |
| secant method | A method of determining the parallel of latitude for the survey of a base-line or standard parallel by offsets from a great-circle line which cuts the parallel at the first and fifth mile corners of the township boundary. See also secant. | HDBK-850 |
| secator | See templet cutter. | HDBK-850 |
| secondary | 1. See secondary great circle. 2. A celestial body revolving around another body, its primary. | HDBK-850 |
| secondary circle | See secondary great circle. | HDBK-850 |
| secondary compilation | A specially prepared matte plastic material used to depict uncorrected or discrete soundings in bathymetric compilation. | HDBK-850 |
| secondary control point (SCP) | A point photographically identifiable, positioned to a high degree of accuracy using an average of several shiran horizontally controlled photographs. Seven to thirteen controlled photographs, each containing the point, are taken over each of four quadridirectional passes intersecting perpendicularly over the point. Photogrammetric measurements are used to determine the position of the point by relating it to the shiran positional nadir point on each photograph. These positions are mathematically averaged to obtain the most probable coordinates for the point. | HDBK-850 |
| secondary great circle | A great circle perpendicular to a primary great circle such as a meridian other than the prime meridian. Also called secondary; secondary circle. | HDBK-850 |
| secondary grid | Any grid, other than the primary grid, required for combined operations application. Tick marks along the neat lines are the preferred method of portrayal. Such grids should remain on the maps or charts so long as the secondary grid remains in use. | HDBK-850 |
| secondary imagery dissemination (SID) | The process for the post-collection electronic transmission or receipt of C3I exploited non-original imagery and imagery-products in other than real or near-real time. | JTA 2.0 |
| secondary quality parameter | Quality parameter specific to certain types of geographic data. | CEN/TC 287 |
| secondary station | An additional triangulation station, usually marked and identified, established to strengthen horizontal map control. Secondary stations are connected to the main scheme stations but are not considered as being part of the main-scheme net. They are often used for providing means for checks and for photogrammetric purposes. | HDBK-850 |
| secondary tide station | A tide station which is operated for a short period of time to obtain data for a specific purpose. | HDBK-850 |
| second-order bench mark | A bench mark connected to the datum (usually mean sea level) by continuous second-order Ieveling or by a continuous combination of first-and second-order leveling. | HDBK-850 |
| second-order leveling | Spirit leveling which does not attain the quality of first-order leveling but does conform to the current specification for second-order (class I or class II) leveling per "Classification Standards of Accuracy and General Specifications of Geodetic Control Surveys." Recommended for densification of the National Network and for localized crustal movement and engineering projects. | HDBK-850 |
| second-order traverse | A survey traverse which extends between adjusted positions of the first-order or second-order control surveys and which conforms to the current specifications for second-order (class I or class II) traverse per "Classification Standards of Accuracy and General Specifications of Geodetic Control Surveys." Recommended for densification of the National Network and metropolitan area surveys. | HDBK-850 |
| second-order triangulation | Second-order triangulation was at one time known as secondary triangulation; changed in 1921 to primary triangulation, and in 1925 to second-order triangulation. These surveys conform to the current specifications for second-order (class I or class II) triangulation per "Classification Standards of Accuracy and General Specifications of Geodetic Control Surveys." Recommended for densification of the National Network and metropolitan area surveys. | HDBK-850 |
| second-order work | The designation given any survey work of next-to-the-highest order of accuracy and precision. | HDBK-850 |
| section | 1. The unit of subdivision of a township with boundaries conforming to the rectangular system of surveys, nominally 1 mile square, containing 640 acres. See also fractional section. 2. (leveling) That portion of a line of levels which is recorded and abstracted as a unit. See also fractional section; half section; quarter section. | HDBK-850 |
| section | A subset of metadata which defines a collection of related metadata. | ISO/TC 211 |
| section corner | A corner at the extremity of a section boundary. | HDBK-850 |
| sectional chart | A series of aeronautical charts at a 1:500,000 scale covering the entire United States, suitable for contact or visual flying. | HDBK-850 |
| sectorial harmonics | The set of spherical harmonics which change from positive to negative as a function of longitude only. See also tesseral harmonics; zonal harmonics. | HDBK-850 |
| secular aberration | The aberration due to the motion of the center of mass of the solar system in space. Also called aberration of fixed stars. | HDBK-850 |
| secular perturbations | Perturbations to the orbit of a planet or satellite that continue to act in one direction without limit, in contrast to periodic perturbations which change direction in a regular manner. | HDBK-850 |
| secular terms | In the mathematical expression of an orbit, terms which are proportional to time, resulting in secular perturbations. | HDBK-850 |
| Secure Communications and Multipurpose Interface | United States Special Operations Command (USSOCOM) fiber-optic-based telecommunications system for dissemination of Command, Control, Communications, Computers, and Intelligence information between headquarters USSOCOM, component commands, major subordinate units, and special operations units. Carries both collateral and SCI voice and data. | USIS 95 |
| Secure Internet Protocol Router Network (SIPRNET) | The data communications component of the DISN [Defense Information System Network] used for secret data. SIPRNET uses the same Internet Protocol routing technology as in NIPRNETwith additional security measures needed to protect classified data transmissions. See also Non-secure Internet Protocol Router Network (NIPRNET). | DII MP |
| secure telephone unit (STU) | A U.S. Government-approved telecommunications terminal that protects the transmission of sensitive or classified information in voice, data, and facsimile systems. | FED STD 1037C |
| Secure Telephone Unit Three (STU-III) | See secure telephone unit (STU). | FED STD 1037C |
| security | The protection of computer resources (e.g., hardware, software, and data) from accidental or malicious access, use, modification, destruction, or disclosure. Tools for the maintenance of security are focused on availability, authentication, accountability, confidentiality, and integrity. | IEEE P1003.0 |
| security | 1. The combination of confidentiality, integrity, and availability. 2. The quality or state of being protected from uncontrolled losses or effects. Note: Absolute security may in practice be impossible to reach; thus the security "quality" could be relative. Within state models of security systems, security is a specific "state" that is to be preserved under various operations. | JTA 2.0 |
| security classification | (UCDM Entity: "SECURITY-CLASSIFICATION") The level assigned to national security information and material that denoted the degree of damage that its unauthorized disclosure would cause to national defense of foreign relations of the United States and the degree of protection required. | USIGS/CDM-A |
| security view | The security viewpoint addresses rules for the protection of information and other resources and the means by which the rules are embodied in the architecture. | IEEE 1471 |
| segment | Predefined and identified set of functionally related data elements values which are identified by their sequential position within the set | CEN/TC 287 |
| segment | 1. One of the subsystems or combinations of subsystems that make up an overall system; for example, the accounts payable segment of a financial system. 2. A collection of data that is stored or transferred as a unit. [IEEE 610.12] | IEEE 610-1990 |
| segment {DII COE} | A collection of one or more CSCIs most conveniently managed as a unit of functionality. Segments are defined from the perspective of an operator, not a developer, and are generally defined to keep related CSCIs together so that functionality may be easily included or excluded. They are usually defined as functional pieces (e.g., a word processor) that make sense from a system administrator perspective because segments are the lowest level components that can be installed on, or removed from, a platform | DII COE IRTS |
| Segment Compliance {DII COE} | The degree to which a segment, whether it is part of the COE or a mission application, is compliant. Compliance of individual segments is computed in order to calculate overall system compliance. | DII COE IRTS |
| Segment Descriptor {DII COE} | An ASCII file which contains information that describes attributes about the segment. The format of these files is described in the I&RTS. Segment descriptor files are processed by various tools in the COE to validate compliance and to perform segment installation. | DII COE IRTS |
| Segment Descriptor Directory {DII COE} | The directory, SegDescrip, which contains the segment descriptor files used to describe a segment to the COE. Each segment is required to contain a segment descriptor directory in order to be DII-compliant. | DII COE IRTS |
| Segment Prefix {DII COE} | A 1-6 alphanumeric character string assigned to each segment for use in naming public symbols. Segment prefixes are used in any situation where it is important to make sure that there will not be a naming conflict between developers (environment variable names, executable file names, shared library names, etc.). Segment prefixes are not necessarily unique among all segments, but the combination of a segment prefix and segment name is always unique among all segments. | DII COE IRTS |
| Segment Servers {DII COE} | One or more designated platforms on a LAN that have segments stored on them in a format that can be used for installation on other platforms. Designation of segment servers greatly simplifies distribution and installation of a system. It also speeds up installation because it can be done from disk across the LAN rather than from slower tape magnetic media. | DII COE IRTS |
| segmentation {DII COE} | The engineering process of decomposing system components into segments and creating the appropriate segment descriptor files. Proper segmentation is vital to a good system design and affects how well the component will operate in the resulting system. | DII COE IRTS |
| selection overlay | A tracing of selected map source detail compiled on transparent material; usually described by the name of the features or details depicted, such as contour overlay, vegetation overlay. Also called lift; pull up; trace. | HDBK-850 |
| selenocentric | Relating to the center of the Moon; referring to the Moon as a center. Also called lunicentric. | HDBK-850 |
| selenocentric coordinates | Quantities which express the position of a point with respect to the center of the Moon. | HDBK-850 |
| selenodesy | (JCS) That branch of applied mathematics which determines, by observation and measurement, the exact positions of points and the figures and areas of large portions of the Moon's surface, or the shape and size of the Moon. | HDBK-850 |
| selenodetic | (JCS) Of or pertaining to, or determined by, selenodesy. | HDBK-850 |
| selenographic | 1. Relating to the physical geography of the Moon. 2. Specifically, referring to positions on the Moon measured in latitude from the Moo''s equator and in longitude from a reference meridian. | HDBK-850 |
| selenology | That branch of astronomy that deals with the Moon, its magnitude, motion, constitution, and the like. | HDBK-850 |
| selenotrope | A device used in geodetic surveying for reflecting the Moo''s rays to a distant point, to aid in long-distance observations. See also heliotrope. | HDBK-850 |
| self-leveling level | A level utilizing the action of gravity in its operation. A prismatic device, called a compensator, is an integral part of the instrument which, once the instrument has been roughly leveled, causes the optical system to swing into proper horizontal line of sight and to maintain that position during readings at a given station. | HDBK-850 |
| self-reading leveling rod | A rod with graduation marks designed to be read by the observer at the leveling instrument. Also called speaking rod. | HDBK-850 |
| self-registering gage | Any tide or stream gage which provides a continuous record of the variation of tide or stream level with the passage of time and which will operate, unattended, for a number of days. Also called automatic gage. | HDBK-850 |
| Semantic Translator | A collection of mappings between a target Information Community and a source Information Community, generally held and maintained by the target Information Community, though both Information Communities may participate in configuring it. Usually expressed in terms of metadata, features, attributes and rules that permit information integration to occur when an feature collection is imported to the target Information Community from a source Information Community. | OpenGIS Guide |
| semianalytical triangulation | The measurement of x-, y-, and z-model coordinates on an analog instrument and the transformation from model coordinates to grid coordinates by a computational procedure. | HDBK-850 |
| semicontrolled mosaic | (JCS) A mosaic composed of corrected or uncorrected prints laid so that major ground features match their geographical coordinates. See also controlled mosaic; mosaic; uncontrolled mosaic. | HDBK-850 |
| semidiameter | 1. The radius of a closed figure. 2. Half the angle at the observer subtended by the visible disk of a celestial body. | HDBK-850 |
| semidiameter correction | A correction due to semidiameter, particularly that sextant altitude correction resulting from observation of the upper or lower limb of a celestial body, rather than the center of that body. | HDBK-850 |
| semidiurnal | Having a period of, occurring in, or related to approximately half a day. | HDBK-850 |
| semidiurnal constituent | A tidal constituent that has two maximums and two minimums each constituent day. | HDBK-850 |
| semimajor axis | 1. One-half the longest diameter of an ellipse. Also called mean distance. 2. (geodesy) Equatorial axis of a spheroid or ellipsoid. | HDBK-850 |
| semiminor axis | One-half the shortest diameter of an ellipse. | HDBK-850 |
| senior intelligence officer | The highest ranking military or civilian individual charged with direct foreign intelligence missions, functions, or responsibilities within a department, agency, component, command, or element of an Intelligence Community organization. | USIS 95 |
| Senior Military Intelligence Officers' Conference | Chaired by the Director, DIA. Attendees include key DoD senior intelligence officers in command and staff positions. | USIS 95 |
| Senior Officials of the Intelligence Community (SOICs) | SOICs are defined as the heads of organizations within the Intelligence Community, as defined by Executive Order 12333, or their designated representatives. | USIS 95 |
| SENIOR YEAR Electro-optical Reconnaissance System | A sensor flown on the U-2R. | USIS 95 |
| sensibility | (spirit level) See sensitivity. | HDBK-850 |
| sensible horizon | That circle of the celestial sphere formed by the intersection of the celestial sphere and a plane through any point, such as the eye of an observer, and perpendicular to the zenith-nadir line. | HDBK-850 |
| sensitive altimeter | See barometric altimeter. | HDBK-850 |
| Sensitive Reconnaissance Operations (SRO) | The use of airborne resources to answer national issues (i.e., treaty monitoring, natural disasters, etc.). | USIS 95 |
| sensitivity | (spirit level) The accuracy and precision which a spirit level is capable of producing. Sensitivity depends on the radius of curvature of its longitudinal section; the longer the radius, the more sensitive the level. Sensitivity is rated by equating the linear length of a division between graduation marks on the level tube and its angular value at the center of curvature of the tube. Also called sensibility. | HDBK-850 |
| sensitometric curve | See characteristic curve. | HDBK-850 |
| sensitometry | The measurement of the response of a photosensitive material to the action of light. | HDBK-850 |
| sensor | A technical means to extend ma''s natural senses. Also a sensing device or equipment which detects and records in the form of imagery, the energy reflected or emitted by environmental areas, features, objects, and events, including natural and cultural features and physical phenomena, as well as man-made features, objects and activities. The energy may be nuclear, electromagnetic, including the visible and invisible portions of the spectrum, chemical, biological, thermal, or mechanical, including sound, blast, and Earth vibration. | HDBK-850 |
| sensor | A technical device designed to detect and respond to one or more particular stimuli and which may record and/or transmit a resultant impulse for interpretation or measurement. | USIS 95 |
| Sensor Calibration Data | Data generated as a result of sensor calibration activity that is subsequently used to maintain sensors and/or in processing image data into imagery. | USIS 95 |
| Sensor Image Simulator (SIS) | A [NIMA] system built by Goodyear (now Loral) to mimic simulators which use DFAD and DTED. SIS merges DFAD and DTED and assigns radar reflectivity. Also used by [NIMA] as an edit station. | HDBK-850 |
| sensor simulation system | A device, such as navigation simulator or trainer, in which specific types of sensor simulator materials are utilized for training purposes. See also sensor simulator materials. | HDBK-850 |
| sensor simulator materials | Those terrain models or maps, factored transparencies or radar reflectivity plates developed or produced from mapping, charting, geodetic, and/or intelligence data or compilations for use in weapon system or navigation simulators or trainers. | HDBK-850 |
| September equinox | See autumnal equinox [(Northern Hemisphere) or vernal equinox (Southern Hemisphere)]. | HDBK-850 |
| sequential data structure | A vector data structure in which each feature in a vector data set as a point, line, or polygon, with its coordinates and attributes all in the same record. No spatial relationships are established between features. Also called spaghetti vector. | HDBK-850 |
| sequential file | file that can only be accessed in a sequential manner | CEN/TC 287 |
| Serial Line Internet Protocol (SLIP) | A protocol which allows IP packets to be exchanged over a serial link or dial-up server. PPP is replacing SLIP. | Multimedia |
| series | See coordinated series; map series. | HDBK-850 |
| series designation | A descriptive title, a number, or a combination of a letter and number, used individually or collectively to identify a group or family of maps, charts, or related publications. | HDBK-850 |
| series specifications | See specifications. | HDBK-850 |
| server | A process implementing one or more operations on one or more objects. | CORBA 2.2 |
| server | A computer program that provides some service. Servers are producers of data while clients are consumers of data. | DII COE IRTS |
| server | A network device that provides service to the network users by managing shared resources. Note 1: The term is often used in the context of a client-server architecture for a local area network (LAN). Note 2: Examples are a printer server and a file server. | FED STD 1037C |
| server object | An object providing response to a request for a service. A given object may be a client for some requests and a server for other requests. | CORBA 2.2 |
| server type | A class of servers in a client/server architecture. [TAFIM 3.0, vol. 4] Among the different types of servers are the following: Name, Directory, Authentication, Access Control, Cryptographic, Communications, Time, File, Data, Print, Mail, Electronic Data Interchange (EDI), Applications, Presentation, and Sensor Monitor/Actuator. | DISA CFS |
| service | A function that is common to a number of programs, such as performing some extensive calculation or retrieving a category of data. An example of a service is a function that accepts a request to transform a point from one coordinate system into another. | DII COE IRTS |
| service | A distinct part of the functionality that is provided by an entity on one side of an interface to an entity on the other side of the interface. | IEEE P1003.0 |
| service area {JTA} | A set of capabilities grouped into categories by function. The JTA defines a set of services common to DoD information systems. | JTA 2.0 |
| session | One or more transactions invoked by a user. | CEN/TC 287 |
| session layer | The fifth layer of the OSI Reference Model. It provides the means for two session service users to organize and synchronize their dialogues and manage the exchange of data. | TAFIM 3.0 |
| set | 1. The direction toward which the current flows. Usually indicated in degrees true or points of the compass. 2. A finite or infinite number of objects of any kind, of entities, or of concepts, that have a given property or properties in common. 3. (surveying) A specified number of observations, as of astronomic azimuth, astronomic longitude. | HDBK-850 |
| set forward | See setup. | HDBK-850 |
| set of coordinates | A set of two or three components identifying a 0-dimensional spatial position (x1,x2[,x3]). | CEN/TC 287 |
| setback | The horizontal distance from the fiducial mark on the front end of a tape or part of tape, which is in use at the time, back to the point on the ground mark or monument to which the particular measure is being made. | HDBK-850 |
| setup | 1. The instrument (transit or level) placed in position and leveled, ready for taking measurements; or a point where an instrument is to be or has been placed. Also called instrument station. 2. In base-line measurements, the horizontal distance from the fiducial mark on the front end of a tape or part of tape which is in use at the time, measured in a forward direction to the point on the ground mark or monument to which the particular measure is being made. Also called set forward. | HDBK-850 |
| sexagesimal system | A system of notation by increments of 60; as the division of the circle into 360 degrees, each degree into 60 minutes, and each minute into 60 seconds. | HDBK-850 |
| sextant | A double-reflecting instrument for measuring angles, primarily altitudes of celestial bodies. As originally used, the term applied only to instruments having an arc of 60° (and a range of 120°), from which the instrument derived its name. In modern practice the term applies to similar instruments, regardless of range. Also called hydrographic sextant. See also bubble sextant; marine sextant; octant; quadrant; quintant; surveying sextant. | HDBK-850 |
| sextant altitude | The altitude of a celestial body as indicated by a sextant or a similar instrument before corrections are applied. | HDBK-850 |
| sextant chart | A chart with curves enabling a graphical solution of the three-point problem rather than using a three-arm protractor. | HDBK-850 |
| shade error | That error of an optical instrument due to refraction in the shade glasses. | HDBK-850 |
| shaded relief | (JCS) A cartographic technique that provides an apparent three-dimensional configuration of the terrain on maps and charts by the use of graded shadows that would be cast by high ground if light were shining from the northwest. Shaded relief is usually used in combination with contours. See also hill shading. | HDBK-850 |
| shaded-relief map | A map on which hypsography is made to appear three-dimensional by the use of graded shadow effects. Generally, the features are shaded as though illuminated from the northwest. A shaded-relief map may also contain contours or hachures in combination with the shading. | HDBK-850 |
| shadow factor | (JCS) A multiplication factor derived from the Sun's declination, the latitude of the target, and the time of photography, used in determining the heights of objects from shadow length. Also called tan alt. | HDBK-850 |
| shadow projector | An optical device developed for checking dimensional accuracy of the various casts of relief models. | HDBK-850 |
| Shared Data Environment (SHADE) | The SHADE is the standards-based architecture that supports one time data entry through reusable Information Technology/data assets and standard data elements. SHADE consists of two components: (1) Shared distributed databases of standard data structures and standard data. (2) Infrastructure components which include shared data dictionary services, transformation software, interfaces, and data warehouses. | DII MP |
| Shared Data Server {DII COE} | A DII-compliant platform that provides data server functions for multiple mission applications. | DII COE IRTS |
| Shared Database Segment {DII COE} | A database segment that supports the information requirements of multiple applications or across multiple database segments. Shared database segments are typically mission-or-functionally-oriented, and are generally specific to a limited number of mission domains. Shared database segments are under joint configuration control. An example of such a database segment is a database of logistics drawings for military hardware. | DII COE IRTS |
| Shared Imagery Repository and Dissemination System | An imagery file server environment at United States Atlantic Command (USACOM). | USIS 95 |
| sheer | Transformation of a rectangle into a parallelogram. | HDBK-850 |
| sheet | A single map, either a complete map in one sheet, or belonging to a series. | HDBK-850 |
| sheet lines | See neatlines. | HDBK-850 |
| shift | (JCS) (radar) The ability to move the origin of a radial display away from the center of the cathode-ray tube. | HDBK-850 |
| shimmer | An atmospheric effect due to atmospheric turbulences. It may be more critical in photographic observations of celestial objects than refraction. The shimmer makes the image fluctuate rapidly. It averages out in the case of long exposures but is serious in case of flashes. Shimmer affects both right ascension and declination in a random manner and, unlike regular refraction, is not zero at the zenith. Also called scintillation. | HDBK-850 |
| Ships Inertial Navigation System (SINS) | A precise dead-reckoning system which maintains ships' position and heading through measurements made with gyroscopes and accelerometers. | HDBK-850 |
| ship-to-shore triangulation | A method of triangulation involving simultaneous observations from three shore stations on a target carried by a ship offshore of the middle station. The middle station must be visible from each of the two end stations. | HDBK-850 |
| shoot | 1. (astronomy; surveying) To make an observation with an instrument. 2. (photography) A slang term used to denote photographing copy, such as a map manuscript, with a copy camera. | HDBK-850 |
| shop calibration | Adjustments to precision instruments made in an instrument maintenance shop having a limited amount of specialized testing equipment. | HDBK-850 |
| shoreline effect | See coastal refraction. | HDBK-850 |
| short arc | A small portion (usually less than half) of the orbital arc traversed by a satellite in making 1 revolution about the Earth. | HDBK-850 |
| short arc geodetic adjustment (SAGA) | The least squares adjustment for position, elevation, azimuth, and distance of a number of stations using Doppler satellite observations of the same passes. The satellite positions are permitted to vary. Only portions of satellite arcs are observed. Points along these short arcs are computed for the times of the observations as an intermediate step towards deriving the station positions. See also point positioning; short arc; short arc network. | HDBK-850 |
| short arc network | A network of positions established by adjustment of simultaneous satellite observations. | HDBK-850 |
| short arc reduction method | A computational procedure in which only short arcs of the satellite orbit are employed in order to minimize the effects of secular and long period perturbations. | HDBK-850 |
| short distance navigational aids | (JCS) An equipment or system which provides navigational assistance to a range not exceeding 200 statute miles/320 kilometers. | HDBK-850 |
| short period perturbations | Periodic perturbations in the orbit of a planet or satellite which execute one complete periodic variation in the time of one orbital period or less. | HDBK-850 |
| short rod | A level rod, usually a Philadelphia rod, permitting readings of 7 feet or less. See also long rod. | HDBK-850 |
| Shuttle Radar Topography Mission (SRTM) | A Space Shuttle mission scheduled to be flown in May 2000 will carry a specially modified SpaceborneImaging Radar-C (SIR-C) system that will produce the most accurate and complete topographic map of Earth's surface ever assembled. The planned 11-day mission is a cooperative project between the National Aeronautics and Space Administration (NASA) and the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense. The mission is designed to collect three-dimensional measurements of nearly 80 percent of the Earth's land surface, except near the poles, with an accuracy of better than 16 meters (53 feet). The SRTM mission will be implemented by the Jet Propulsion Laboratory (JPL) for NASA's Office of Mission to Planet Earth, Washington, DC. | JPL Web Site |
| side can sonar | A system utilizing sonar transducers mounted nearly horizontally and perpendicular to the line of travel, to portray bottom features to the side of the survey vessel. | HDBK-850 |
| side equation | A condition equation which expresses the relationship between the various sides in a triangulation figure as they can be derived by computation from one another. | HDBK-850 |
| side equation tests | Side equation tests are a modification of side equations which are helpful to geodetic field parties in checking the accuracy of observations and in locating the points where horizontal-direction observations may be in error. | HDBK-850 |
| side line | Applied to a strip of land such as a street or right-of-way, it defines the boundaries of that strip; not applied to the ends of a strip. | HDBK-850 |
| side overlap | Also called side lap. See overlap, definition 1. | HDBK-850 |
| side shot | A reading or measurement from a survey station to locate a point which is not intended to be used as a base for the extension of the survey. A side shot is usually made for the purpose of determining the position of some object which is to be shown on the map. | HDBK-850 |
| side test | In triangulation of a quadrilateral or similar figure, where distances can be computed two different ways, the ratio of the difference between the two computed results to the length of the line. | HDBK-850 |
| Side-Looking Airborne Radar (SLAR) | (JCS) An airborne radar, viewing at right angles to the axis of the vehicle, which produces a presentation of terrain or moving targets. | HDBK-850 |
| sidereal | Of or pertaining to the stars. Although sidereal generally refers to the stars and tropical to the vernal equinox, sidereal time and the sidereal day are based upon the position of the vernal equinox relative to the meridian. | HDBK-850 |
| sidereal day | The interval of time from a transit of the (true) vernal equinox across the upper branch of a given meridian to its next successive transit across the upper branch of the same meridian. Also called equinoctial day. | HDBK-850 |
| sidereal focus | The position of the principal focal plane of a lens system. A camera or telescope is in sidereal focus when incident rays from a great distance come to a focus in the plane of the photographic plate or of the reticle. Also called solar focus. | HDBK-850 |
| sidereal hour angle (SHA) | Angular distance west of the vernal equinox; the arc of the celestial equator, or the angle at the celestial pole, between the hour circle of the vernal equinox and the hour circle of a point on the celestial sphere, measured westward from the hour circle of the vernal equinox through 360°. | HDBK-850 |
| sidereal month | The interval of time between two successive passages of the Moon past a fixed star. | HDBK-850 |
| sidereal period | 1. The time taken by a planet or satellite to complete one revolution about its primary and as referred to a fixed star. 2. Specifically, the interval between two successive returns of an Earth satellite in orbit to the same geocentric right ascension. | HDBK-850 |
| sidereal time | Time based upon the rotation of the Earth relative to the vernal equinox. | HDBK-850 |
| sidereal year | The period of one apparent revolution of the Earth around the Sun, with respect to the fixed stars, with an accepted value of 365 days, 6 hours, 9 minutes, 9.5 seconds in 1900; and increasing at the rate of 0.0001 second annually. | HDBK-850 |
| side-sight | A sight made with the transit to a point not on the line of traverse. It may be a side shot or an observation to locate an in-and-out station, an azimuth mark, or an intersected point. | HDBK-850 |
| sight | Observation of the altitude, and sometimes also the azimuth, of a celestial body for a line of position; or the data obtained by such observation. | HDBK-850 |
| sight lamp | A compact, portable, battery-operated electric lamp used as a target for observations on surveys of high precision (usually on first- and second-order geodetic triangulation). The parabolic reflector is mounted in a special case to facilitate pointing and adjusting. | HDBK-850 |
| sight line | See line of collimation. | HDBK-850 |
| sight reduction | The process of deriving from observation of a celestial body the information needed for establishing a line of position. | HDBK-850 |
| sight reduction tables | Tables for performing sight reductions, particularly those for determining computed altitude for comparison with the observed altitude of a celestial body to determine the altitude difference for establishing a line of position. | HDBK-850 |
| sight rod | See range rod. | HDBK-850 |
| sight tree | See line tree. | HDBK-850 |
| signals intelligence (SIGINT) | (DOD) 1. A category of intelligence comprising either individually or in combination all communications intelligence, electronics intelligence, and foreign instrumentation signals intelligence, however transmitted. 2. Intelligence derived from communications, electronics, and foreign instrumentation signals. See also communications intelligence (COMINT); electronics intelligence (ELINT); intelligence; foreign instrumentation signals intelligence (FISINT). | JPUB 1-02 |
| signal-to-noise ratio (S/N) | (DOD) The ratio of the amplitude of the desired signal to the amplitude of noise signals at a given point in time. | JPUB 1-02 |
| signature | Defines the parameters of a given operation including their number order, data types, and passing mode; the results if any; and the possible outcomes (normal vs. exceptional) that might occur | CORBA 2.2 |
| signature | The characteristics or patterns of physical features that permit objects to be recognized on aerial imagery. A category is said to have a signature only if the characteristic pattern is highly representative of all units of that category. | HDBK-850 |
| significant date | The date that represents the best approximation of the date of the product's information; e.g., the date of compilation or the date of the source materials used to revise the product. | HDBK-850 |
| simple conic chart | A chart on a simple conic projection. | HDBK-850 |
| simple conic map projection | A conic map projection in which the surface of a sphere or spheroid, such as the Earth, is conceived as developed on a tangent cone, which is then spread out to form a plane. | HDBK-850 |
| simple feature | See feature. | HDBK-850 |
| simple harmonic motion | The projection of uniform circular motion on a diameter of the circle of such motion. | HDBK-850 |
| Simple Mail Transfer Protocol (SMTP) | The TCP/IP protocol for transferring electronic mail messages from one machine to another. SMTP specifies how two mail systems interact and the format of control messages they exchange to transfer mail. [DISA/DO3 (CIO)] | DISA CFS |
| Simple Network Monitoring Protocol (SNMP) | A standard protocol used to monitor IP gateways and the networks to which they attach. [Comer] [DISA/DO3 (CIO)] | DISA CFS |
| simple pendulum | A theoretical concept. A heavy particle suspended from a fixed point by a fine thread which is inextensible and without weight. A simple pendulum cannot be realized in actual work. A simple pendulum is, however, the basis of reductions of observations made with an actual pendulum. Those observations have corrections applied to them to obtain results which would have been produced by an equivalent simple pendulum. | HDBK-850 |
| simplification | Smoothing the character of features without destroying their visible shape. Simplification increases as map scale decreases. | HDBK-850 |
| Simpson's 1/3 rule | A mathematical expression for determining areas between an irregular boundary and a traverse line where equally spaced offset measurements have been taken. | HDBK-850 |
| Simulation Object Model (SOM) | A specification of the intrinsic capabilities that an individual simulation offers to federations. The standard format in which SOMs are expressed provides a means for federation developers to quickly determine the suitability of simulation systems to assume specific roles within a federation. (HLA Glossary, www.dmso.mil/projects/hla/docslib/hlagloss.html) | JTA 2.0 |
| simultaneous altitudes | Altitudes of two or more celestial bodies observed at the same time. | HDBK-850 |
| simultaneous double line | See simultaneous level line. | HDBK-850 |
| simultaneous level line | A line of spirit leveling composed of two single lines run over the same route, both in the same direction, but using different turning points. Also called simultaneous double line. | HDBK-850 |
| simultaneous mode | A satellite method for determining the position of an unknown station by the simultaneous ranging from three stations of known position and the unknown station, or simultaneously observing direction from two stations of known position and the unknown station, and mathematically reducing the data to solve for a line or surface of position of the unknown. This technique permits position determination independent of a satellite's orbital parameters. | HDBK-850 |
| simultaneous observations | (satellite) Observations of a satellite that are made from two or more distinct points or tracking stations at exactly the same time. | HDBK-850 |
| single astronomic station datum orientation | The orientation of a geodetic datum by accepting the astronomically determined coordinates of the origin and the azimuth to one other station without any correction. | HDBK-850 |
| single inheritance | The construction of a definition by incremental modification of one definition. Contrast with multiple inheritance. | CORBA 2.2 |
| Single Integrated Operational Plan (SIOP) | Incorporates all supporting forces for warfighting, to include targeting. | USIS 2-1.1 |
| single proportionate measurement | A method of proportioning measurements in the restoration of a lost corner whose position is determined with reference to alignment in one direction. Examples of such corners are quarter section corners on the line between two section corners, all corners on standard parallels, and all intermediate positions on any township boundary line. The ordinary field problem consists of distributing the excess of deficiency between two existent corners in such a way that the amount given to each interval shall bear the same proportion to the whole difference as the record length of the interval bears to the whole record distance. After having applied the proportionate difference to the record length of each interval, the sum of the several parts will equal the new measurement of the whole distance. | HDBK-850 |
| single-base method | A technique of barometric leveling utilizing two barometers. One barometer is designated as a base and a second, or roving, barometer is used to determine pressures at specific points. Time and pressure arc recorded at each position occupied by the roving barometer and time and pressure are recorded every 5 minutes by the base barometer. Data are reduced to elevations by office computations. See also barometric leveling. | HDBK-850 |
| single-heading radar prediction | A radar prediction made for a single aircraft position or from one specific point in relation to the target. It may be either an experience or an analytical prediction. | HDBK-850 |
| single-model instrument | A general class of stereoscopic plotting instruments with a capability for projecting a single stereomodel per setup. This class of plotter is designed for compilation only and is dependent upon supplementary photogrammetric techniques to accomplish necessary stereotriangulation. | HDBK-850 |
| single-point transfer instrument | Any instrument used for the transfer of planimetric detail from a single photograph. These instruments are of two general types, reflecting projector and camera lucida. | HDBK-850 |
| single-projector method | See one-swing method. | HDBK-850 |
| single-target leveling rod | Any target rod having graduations on one face only. | HDBK-850 |
| sinusoidal map projection | A particular type of the Bonne map projection, employing the Equator as the standard parallel, and showing all geographic parallels as truly spaced parallel straight lines, along which exact scale is preserved. This is an equal-area map projection. Also called Mercator equal-area map projection. See also Sanson-Flamsteed map projection. | HDBK-850 |
| siphon barometer | A mercury barometer consisting of a column of mercury in a glass tube which is bent so as to have two vertical branches, one about one-fourth the length of the other. The end of the longer branch is closed, and the air in it is displaced by the mercury, but the shorter branch is left open, and the mercury is thereby subjected to atmospheric pressure. The difference of the height of the mercury in the two branches is a measure of the atmospheric pressure. | HDBK-850 |
| situation map | (JCS) A map showing the tactical or administrative situation at a particular time. See also map. | HDBK-850 |
| sixteenth section corner | A corner at an extremity of a boundary of a quarter-quarter section; midpoint between or 20 chains from the controlling corners on the section or township boundaries. Written as 1/16 section corner. Also called quarter-quarter section corner. | HDBK-850 |
| size | 1. To coat with any of the various glutinous materials used for filling the pores in the surface of paper, fiber, or of a mosaicking board. 2. To calculate the measurements required in photographing a map to a desired scale. | HDBK-850 |
| sizing the litho | An operation performed in order to determine the actual measurement of the original lithographic maps to be used as source for a map revision in order to determine what distortion and changes of dimensions are necessary to fit the old map inside the new projection. | HDBK-850 |
| skeleton | The object-interface-specific ORB component which assists an object adapter in passing requests to particular methods. | CORBA 2.2 |
| sketch map | A map made from loose, uncontrolled surveys. The information thereon is generally sparse. | HDBK-850 |
| sketchmaster | A form of camera lucida that permits superimposition of a rectified virtual image of a photograph over a map manuscript. See also oblique sketchmaster; universal analog photographic rectification system; universal sketchmaster; vertical sketchmaster. | HDBK-850 |
| skewed map projection | Any standard projection used in map or chart construction which does not conform to a general north-south format with relation to the neatlines of the map or chart. | HDBK-850 |
| slant range | The line of sight distance between two points, not at the same level relative to a specific datum. The line of sight distance measured in nautical miles from a vehicle to the target. | USIS 95 |
| slave station | That station in a given system of stations that is controlled by the master station. Also called remote station. | HDBK-850 |
| slivers | (digital) Polygons formed when two adjacent polygons do not abut along a single common line and leave a small space between the larger two. | HDBK-850 |
| slope | See gradient or grazing angle. | HDBK-850 |
| slope angle | The angle between a slope and the horizontal. | HDBK-850 |
| slope chaining | See slope taping. | HDBK-850 |
| slope correction | 1. (hydrographic surveying) The correction applied to soundings erroneously positioned as a result of an echo sounder receiving its initial return from a point upslope from its recorded position. 2. (land surveying) See grade correction. | HDBK-850 |
| slope correction of tape | See grade correction. | HDBK-850 |
| slope taping | Taping wherein the tape (or chain) is held as required by the slope of the ground, the slope of the tape measured, and the horizontal distance computed. Also called slope chaining. | HDBK-850 |
| slot cutter | See templet cutter. | HDBK-850 |
| slotted templet | A templet on which the radials are represented as a slot cut in a sheet of cardboard, metal, or other material. | HDBK-850 |
| slotted-templet plot | See slotted-templet triangulation. | HDBK-850 |
| slotted-templet triangulation | A graphical radial triangulation made by the use of slotted templets. Also called slotted-templet plot. | HDBK-850 |
| small circle | A circle on the surface of the Earth, the plane of which does not pass through the Earth's center. | HDBK-850 |
| Small Computer System Interface (SCSI) | A type of controller system that enables users to connect devices to their computer. | Multimedia |
| Small Spacecraft Technology Initiative (SSTI) | The SSTI was developed by the National Aeronautics and Space Administation (NASA) Office of Space Access and Technology to advance the state of technology and reduce the costs associated in the design, integration, launch, and operation of small satellites. TRW and CTA Space Systems were each awarded a contract from NASA to design and launch two small earth-observing satellites named Lewis (TRW) and Clark (CTA). Lewis was outfitted with advanced Earth-imaging instruments, including a 30-meter-resolution, 384-spectral-channel hyperspectral imager; an Ultraviolet Cosmic Background Radiometer; and a 300-meter-resolution, 256-spectral-channel Linear Etalon Imaging Spectral Array. Lewis was designated to be the world's first publicly accessible spaceborne hyperspectral sensor. The Lewis spacecraft was launched on August 22, 1997. The spacecraft developed a slow spin on August 26 and the spacecraft re-entered the Earth's atmosphere and presumably burned up on September 28, 1997. Clark will have a high-resolution panchromatic imager with 3-meter resolution and a multispectral imager with 15-meter resolution and cloud editing capability. It will also have the following instuments: µ MAPS (Micro-Measuring Air Pollution From Satellites); X-Ray Spectrometer (Soft and Gamma); and Atmospheric Tomography (3-D Pollution Mapping). Clark is scheduled for launch in Spring of 1998. | NASA Web Site |
| Small Wetted Area Twin Hull (SWATH) | A vessel designed for stability by having its buoyant volume mostly underwater, presently being evaluated for use in hydrographic surveying projects. | HDBK-850 |
| Small Wetted Area Twin Hull (SWATH) survey | See multibeam survey. See also Small Wetted Area Twin Hull (SWATH). | HDBK-850 |
| small-scale map | A map having a scale of 1:600,000 or smaller. | HDBK-850 |
| smooth sheet | A final plot of field control and hydrographic development such as; soundings, fathom curves, wire drag areas, etc., to be used in chart construction. | HDBK-850 |
| smoothing | 1. A set of procedures for removing short-range, erratic variations from lines, surfaces, or data series. 2. (image processing) The averaging of densities in adjacent areas to produce more gradual transitions. | HDBK-850 |
| snakeslip | See etch slip. | HDBK-850 |
| snap marker | See point marker. | HDBK-850 |
| Snel''s law of refraction | This law states that the sine of the angle of incidence divided by the sine of the angle of refraction equals a constant termed the index of refraction when one of the media is air. The index of refraction can also be explained as the ratio of the velocity of light in one medium to that in another. | HDBK-850 |
| socket | A software interface between an application and TCP/IP protocols. An application opens a socket, specifies the service desired, binds the socket to a specific destination, and then sends or receives data. [Comer] [DISA/DO3 (CIO)] | DISA CFS |
| softcopy | Products which are maintained in digital format for use with automated data processing equipment. | HDBK-850 |
| software | The programs, procedures, rules, and any associated documentation pertaining to the operation of an information processing system. | IEEE P1003.0 |
| software engineering environment | The supporting hardware, software, and firmware used in the production of software throughout its life cycle. | S/W Reuse |
| solar altitude | Angular distance of the Sun above the horizon. | HDBK-850 |
| solar attachment | An auxiliary instrument which may be attached to an engineer's transit, permitting its use as a solar compass. | HDBK-850 |
| solar day | 1. The duration of one rotation of the Earth on its axis, with respect to the Sun. This may be either a mean solar day, or an apparent solar day, as the reference is the mean or apparent sun, respectively. See also apparent solar day; mean solar day. 2. The duration of one rotation of the Sun. | HDBK-850 |
| solar declination | Angular distance of the Sun expressed in degrees north or south of the celestial equator; it is indicated as "+" when north and "-" when south of the Equator. Also called declination of the Sun. | HDBK-850 |
| solar eclipse | The obscuration of the light of the Sun by the Moon. A solar eclipse is partial if the Sun is partly obscured; total if the entire surface is obscured; or annular if a thin ring of the Sun's surface appears around the obscuring body. | HDBK-850 |
| solar eclipse method | A means of determining the angular distance between two observers along the center line of the path of a solar eclipse. | HDBK-850 |
| solar ephemeris | A daily tabulation of astronomic positions of the Sun. | HDBK-850 |
| solar focus | See sidereal focus. | HDBK-850 |
| solar occultation | An occultation of the Sun by the Moon. | HDBK-850 |
| solar parallax | The angle subtended by the equatorial radius of the Earth at a distance of one astronomic unit (i.e., the equatorial horizontal parallax of the Sun). | HDBK-850 |
| solar radiation pressure | A perturbation of high flying artificial satellites of large diameter. The greater part is directly from the Sun, a minor part is from the Earth, which is usually divided into direct (reflected) and indirect terrestrial (radiated) radiation pressures. | HDBK-850 |
| solar time | 1. Time based upon the rotation of the Earth relative to the Sun. 2. Time on the Sun. | HDBK-850 |
| solar transit | A regular transit to which has been added a solar attachment, which effects the instantaneous mechanical solution of the astronomic triangle (Sun-zenith-pole) and permits the establishment and surveying of the astronomic meridian or astronomic parallel directly by observation. | HDBK-850 |
| solar year | See tropical year. | HDBK-850 |
| solid angle | The integrated angular spread at the vertex of a cone, pyramid, or other solid figure. | HDBK-850 |
| solstice | One of two points of the ecliptic farthest from the celestial equator; one of the two points on the celestial sphere occupied by the Sun at maximum declination. Also called solstitial point. See also summer solstice; winter solstice. | HDBK-850 |
| solstitial colure | The hour circle through the solstices. | HDBK-850 |
| solstitial point | See solstice. | HDBK-850 |
| sonar | 1. (JCS) A sonic device used primarily for the detection and location of underwater objects. 2. A system for determining distance of an underwater object by measuring the interval of time between transmission of an underwater sonic or ultrasonic signal and return of its echo. [This term is derived form the words "sound navigation and ranging."] | HDBK-850 |
| sonic depth finder | See echo sounder. | HDBK-850 |
| sonic navigation | See acoustic navigation. | HDBK-850 |
| sortie | (JCS) In air operations, an operational flight by one aircraft. | HDBK-850 |
| sortie plot | (JCS) An overlay representing the area on a map covered by imagery taken during one sortie. Also called photo index. | HDBK-850 |
| Sound Surveillance Systems Charts (SOSUS) | Charts which portray generalized bathymetry and other prescribed system oriented information supporting Anti Submarine Warfare (ASW) surveillance. | HDBK-850 |
| sounding | 1. The measured or charted depth of water. 2. A measurement of the depth of water expressed in feet or fathoms and reduced to the tidal datum shown in the chart title. Also called hydrographic sounding. See also depth; depth number. 3. In geophysics, any penetration of the natural environment for scientific observation. See also echo sounder; echo sounding; lead line; off soundings; on soundings; wire drag. | HDBK-850 |
| sounding datum | The plane to which soundings are referred. | HDBK-850 |
| sounding pole | A round, wooden, 15-foot-long pole, used for shoal water soundings. It is graduated in feet and half-feet from the center toward both ends and numbered consecutively from the ends toward the center. | HDBK-850 |
| Source Acquisition Segment (SA/S) | Segment of NIMA's DPS which provides the capability to manage image library holdings and to maintain the geodetic control data base. See also Digital Production System (DPS). | HDBK-850 |
| source map | The map used for the selection of map or chart detail. | HDBK-850 |
| source material | Data of any type required for the production of MC&G products including, but not limited to, ground control, aerial and terrestrial photographs, sketches, maps, and charts; topographic, hydrographic, hypsographic, magnetic, geodetic, oceanographic, and meteorological information; intelligence documents and written reports pertaining to natural and man-made features of the area to be mapped or charted. | HDBK-850 |
| Source Preparation Segment (SP/S) | Segment of NIMA's DPS which provides the capability to accomplish source assessment, source refinement, and geopositioning. Operators perform assessment of imagery and of textual and graphics material to determine their characteristics and utility. This segment also provides for mensuration to support triangulation with the existing Hardcopy Exploitation Segment. See also Digital Production System (DPS); MARK 90; Hardcopy Exploitation Segment (HE/S). | HDBK-850 |
| south declination | See declination, definition 3. | HDBK-850 |
| south geographical pole | The geographical pole in the Southern Hemisphere, at latitude 90°S. | HDBK-850 |
| south geomagnetic pole | The geomagnetic pole in the Southern Hemisphere. | HDBK-850 |
| south magnetic pole | The magnetic pole in the Southern Hemisphere. | HDBK-850 |
| south point | See celestial meridian. | HDBK-850 |
| south polar circle | See Antarctic Circle. | HDBK-850 |
| southbound node | See descending node. | HDBK-850 |
| Southern Air Forces | See Twelfth Air Force (12AF). | 12AF Web Site |
| southing | See latitude difference. | HDBK-850 |
| space coordinates | Any general three-dimensional coordinate system used to define the position of a point in the object space, as distinguished from the image of the point on a photograph. | HDBK-850 |
| Space Information - 2 Meter (SPIN-2®) | SPIN-2 is panchromatic, 2 meter resolution Russian satellite image data that is digitized and ortho-rectified. The SPIN-2 trademark is owned jointly by SOVINFORMSPUTNIK (Moscow, Russia), Aerial Images, Inc (Raleigh, NC) and Central Trading Systems Inc. (Huntington Bay, NY). The two cameras used are the KVR-1000 Camera and the TK-350 Camera. | SPIN-2 Web Site |
| space motion | Motion of a celestial body through space. See also proper motion. | HDBK-850 |
| space oblique Mercator projection | A mapping projection modeled on the dynamics of the LANDSAT spacecraft motion. It incorporates time-dependent values of satellite platform motion and the Earth's motion in a continuous projection of the area viewed in the LANDSAT scene. | HDBK-850 |
| space-polar coordinates | A system of coordinates by which a point on the surface of a sphere is located in space by (1) its distance from a fixed point at the center, called the pole; (2) the colatitude or angle between the polar axis (a reference line through the pole) and the radius vector (a straight line connecting the pole and the point); and (3) the longitude or angle between a reference plane through the polar axis and a plane through the radius vector and polar axis. | HDBK-850 |
| spading | Removing scribe coating from the base material by use of a wide flat blade. | HDBK-850 |
| spaghetti vector | A digital storage format in which all lines and points are unrelated to each other. | HDBK-850 |
| spatial analysis | Analytical techniques associated with the study of the location of geographical entities together with their spatial dimensions. Also referred to as quantitative analysis. | HDBK-850 |
| spatial attribute | A feature attribute describing the spatial representation of the feature by coordinates, mathematical functions and/or boundary topology relationships. | ISO/TC 211 |
| spatial auto-correlation | The correlation between data at spatially different locations. | ISO/TC 211 |
| spatial coordinate system | A system of providing basic numeric primitives for describing width, length, and height; the basic dimensions of space. | ISO/TC 211 |
| spatial data | Data pertaining to the location of geographical entities together with their spatial dimensions. Spatial data are classified as point, line, area or surface. | HDBK-850 |
| spatial data bases | Collections of similar and related spatial data records that are recorded for use by a computer. See also Geographic Information System (GIS). | HDBK-850 |
| spatial data manipulation language | A data manipulation language (DML) with additional functions suitable for combinations of spatial and non-spatial data. An SDML may be created by extending an existing DML by the addition of the functions and predicates defined in this standard. | CEN/TC 287 |
| spatial data sets | Collections of similar and related spatial data records that are recorded for use by a computer. | HDBK-850 |
| Spatial Data Transfer Specification (SDTS) | A specification under the Spatial Data Transfer Standard (SDTS) designed to meet the recognized requirement for easy transfer of spatial data from one spatial data handling system to another, with both systems possibly residing on computer hardware and operating system software of different makes. Under SDTS, the contents (specification of fields and subfields) are clearly separated from the implementation (the encoding of fields and subfields on the media).See Spatial Data Transfer Standard (SDTS). | HDBK-850 |
| Spatial Data Transfer Standard (SDTS) | A standard consisting of definitions and references, the Spatial Data Transfer Specification, a quality report on digital cartographic data, a conceptual model for describing cartographic features, and a standard set of defined entities and attributes derived from topographic maps and general nautical charts. See Spatial Data Transfer Specification (SDTS). | HDBK-850 |
| spatial datum | Any datum which serves as a reference for coordinate position information. | CEN/TC 287 |
| spatial model | See stereoscopic model. | HDBK-850 |
| spatial object | A collection of spatial primitives that represents the spatial characteristics of a geographic feature. | ISO/TC 211 |
| spatial operation | A well-defined function or procedure that either uses or creates spatial objects. | ISO/TC 211 |
| spatial operator | The name by which a spatial operation is referenced. | ISO/TC 211 |
| spatial position | A position in space based either on coordinates of two or three dimensions in a mathematically defined system or on indirect position. | ISO/TC 211 |
| spatial primitive | A non-decomposed object used in describing the spatial characteristics of a geographic feature. | ISO/TC 211 |
| spatial property | Characteristics of a geographic feature that relate to its geometry. NOTE - This geometry may include; position, shape, orientation, dimension, decomposability, self-similarity, and scalability. | ISO/TC 211 |
| spatial reference | A label or geocode which identifies an occurrence of a spatial unit. | ISO/TC 211 |
| spatial reference system | A description of how geographic objects are positioned in space. | CEN/TC 287 |
| spatial referencing scheme | A collection of spatial units with a common theme. EXAMPLE: NUTS, the Nomenclature of Territorial Units for Statistics. | CEN/TC 287 |
| spatial subschema | A conceptual schema for the spatial characteristics of geographic information. | ISO/TC 211 |
| spatial unit | 1. A class of features that represents the indirect spatial position of another features. 2. Sub-division of an area according to value of a particular property. | ISO/TC 211 |
| spatial view | A set of instances of geometric primitives and/or structure primitives conforming to a pre-defined conceptual geometry sub-schema. | ISO/TC 211 |
| Spatially Modulated Imaging Fourier Transform Spectrometer | A pushbroom imaging spectrometer that collects hyperspectral data in the 1- to 5-micron region of the electromagnetic spectrum. The sensor, developed under ARPA/ONR funding at the University of HI [Hawaii], operates in two modes, collecting 90 channels from 1 to 5 microns with 100-wave number resolution, or 50 channels from 3 to 5.3 microns with 50 wave number resolution. The instantaneous field of view (IFOV) of the sensor is .5 mrad and has a swath width of 256 pixels. | USIS 95 |
| speaking rod | See self-reading leveling rod. | HDBK-850 |
| special area (SA) annotation | A structure or group of structures possessing unique physical characteristics, but whose area or linear dimensions do not qualify for application of one of the radar significance analysis codes. | HDBK-850 |
| special boat unit | Those U.S. Navy forces organized, trained, and equipped to conduct or support naval special warfare, riverine warfare, coastal patrol and interdiction, and joint special operations with patrol boats or other combatant craft designed primarily for special operations support. | USIS 95 |
| Special Imagery Interpretation Report (SIIR) | A hardcopy reporting product that distributes a single, detailed, analytic report based on, but not limited to, imagery derived information pertaining to a target or topic of special interest. | USIS 2-1.1 |
| special intelligence | An unclassified term used to designate a category of sensitive compartmented information (SCI) | USIS 95 |
| Special Intelligence Communications | Established by Secretary of Defense Memorandum, 4 November 1964. It consists of those communications facilities under the operational and technical control of the chief of intelligence of each of the military departments and under the management of DIA. | USIS 95 |
| special job-cover map | (JCS) A small-scale map used to record progress on photographic reconnaissance tasks covering very large areas. As each portion of the task is completed, the area covered is outlined on the map. | HDBK-850 |
| special meander corner | A corner established at the intersection of a surveyed subdivision-of-section line and a meander line or the intersection of a computed center line of a section and a meander line. In the latter case, the centerline of the section is calculated and surveyed on a theoretical bearing to an intersection with the meander line of a lake (over 50 acres in area) which is located entirely within a section. | HDBK-850 |
| Special Operation Forces | Units from the U.S. Armed Forces that are specially trained, equipped, and organized to conduct operations against strategic or tactical targets in pursuit of national military, political, or psychological objectives. | USIS 95 |
| Special Operational Forces Air Training System | A training system employed by Special Operation Forces air forces that includes the use of image perspective transformation. | USIS 95 |
| special operations command | A subordinate unified or other joint command established by a joint force commander to plan, coordinate, conduct, and support joint special operations within the joint force commander's assigned area of operations. | USIS 95 |
| Special Operations Command Southern Command | A Joint Component Command under United States Southern Command (USSOUTHCOM) located "forward" at Albrook Air Force Station, Panama. | USIS 95 |
| Special Operations Forces Atlantic | An inactive joint component command under United States Atlantic Command (USACOM). | USIS 95 |
| special-purpose map | Any map designed primarily to meet specific requirements. | HDBK-850 |
| special-subject map | See topical map. | HDBK-850 |
| specific force | The difference between the inertial acceleration and gravitation acting on a body. The physical gravity sensed by accelerometers. All spirit levels are normal to the specific force vector. | HDBK-850 |
| specification | A document that specifies, in a complete, precise, verifiable manner, the requirements, design, behavior, or other characteristics of a system or component, and, often, the procedures for determining whether these provisions have been satisfied. [IEEE 610.12] | IEEE 610-1990 |
| specification | (UCDM Entity: "SPECIFICATION") A description of the parameters within which a product should be created or raw data captured. | USIGS/CDM-A |
| specifications | The rules, regulations, symbology, and a comprehensive set of standards which have been established for a particular map or chart series or scale group. Specifications vary with the scale and the purpose of the graphic. | HDBK-850 |
| spectral band | A set of adjacent wavelengths in the electromagnetic spectrum with a common characteristic, such as the visible band. | HDBK-850 |
| spectral diversity | A full range of spectral regions. | USIS 95 |
| spectral phenomenology | Physical phenomena allowing the identification of unique observable parameters for identification of targets, characterization of materials, and determination of other useful information. | USIS 95 |
| spectral signature | A quantitative measurement of the properties of an object at one or several wavelength intervals. | USIS 95 |
| spectrometer | A device to measure the spectral distribution of electromagnetic radiation. See imaging spectrometry. | USIS 95 |
| spectrophotometer | A device for the measurement of spectral transmittance, spectral reflectance, or relative spectral emittance. | HDBK-850 |
| spectroradiometer | A device for the measurement of spectral distribution of radiant energy. | HDBK-850 |
| Spectroradiometric Working Group | A working group dedicated to the research and development of spectral exploitation. | USIS 95 |
| spectrozonal photography | A photographic technique whereby the natural spectral emissions of all objects are selectively filtered in order to image only those objects within a particular spectral band or zone and eliminate the unwanted background. | USIS 95 |
| specular reflection | (optics or microwave theory) The type of reflection characteristic of a highly polished plane surface from which all rays are reflected at an angle equal to the angle of incidence. See also diffuse reflection. | HDBK-850 |
| speed | (photography) The response or sensitivity of the material to light, often expressed numerically according to one of several systems (e.g., H and D, DIN, Scheiner, and ASA exposure index). See also relative aperture. | HDBK-850 |
| speed of lens | See relative aperture. | HDBK-850 |
| sphere | A body or the space bounded by a spherical surface. See also celestial sphere; oblique sphere; parallel sphere; right sphere; terrestrial sphere. | HDBK-850 |
| spherical aberration | An aberration caused by rays from various zones of a lens coming to focus at different places along the axis. This results in an object point being imaged as a blurred circle. | HDBK-850 |
| spherical angle | The angle between two intersecting great circles. | HDBK-850 |
| spherical coordinates | A system of polar coordinates in which the origin is the center of a sphere and the points all lie on the surface of the sphere. The polar axis of such a system cuts the sphere at its two poles. In photogrammetry, spherical coordinates are useful in defining the relative orientation of perspective rays or axes and make it possible to state and solve, in simple forms, many related problems. | HDBK-850 |
| spherical excess | The amount by which the sum of the three angles of a triangle on a sphere exceeds 180°. In geodetic work, in the computation of triangles, the difference between spherical angles and spheroidal angles is generally neglected; spherical angles are used, and Legendre's theorem is applied to the distribution of the spherical excess. That is, approximately one-third of the spherical excess of a given spherical triangle is subtracted from each angle of the triangle. | HDBK-850 |
| spherical harmonics | Trigonometric terms of an infinite series used to approximate a two- or three-dimensional function of locations on or above the Earth. | HDBK-850 |
| spherical lens | A lens in which all surfaces are segments of spheres. | HDBK-850 |
| spherical triangle | The closed figure formed when any three points on the surface of a sphere are joined by arcs of great circles. | HDBK-850 |
| spheroid | 1. (general) Any figure differing slightly from a sphere. 2. (geodesy) A mathematical figure closely approaching the geoid in form and size and used as a surface of reference for geodetic surveys. In geodesy spheroid and ellipsoid are synonymous terms. See also Airy spheroid (ellipsoid); Australian National spheroid; Bessel spheroid (ellipsoid); Clarke spheroid (ellipsoid) of 1866; Clarke spheroid (ellipsoid) of 1880; ellipsoid of rotation; equilibrium spheroid; Everest spheroid (ellipsoid); Hayford spheroid (ellipsoid); International spheroid (ellipsoid); Krasovsky spheroid (ellipsoid); oblate spheroid; prolate spheroid; reference spheroid. | HDBK-850 |
| spheroid junction | An accentuated line on a map or chart, separating two or more major grids which are based on different spheroids. | HDBK-850 |
| spheroid of reference | See reference spheroid. | HDBK-850 |
| spheroidal angle | An angle between two curves on a spheroid; measured by the angle between their tangents at the point of intersection. | HDBK-850 |
| spheroidal excess | The amount by which the sun of the three angles of a triangle on a spheroid exceeds 180°. See also spherical excess. | HDBK-850 |
| spheroidal triangle | A triangle on the surface of a spheroid. | HDBK-850 |
| spherop | An equipotential surface in the normal gravity field of the Earth. Also called spheropotential surface. | HDBK-850 |
| spheropotential surface | See spherop. | HDBK-850 |
| spider templet | A mechanical templet which is formed by attaching slotted steel arms, representing radials, to a central core. The spider templet can be disassembled and the parts used again. Also called mechanical arm templet. | HDBK-850 |
| spider-templet plot | See spider-templet triangulation. | HDBK-850 |
| spider-templet triangulation | A graphical radial triangulation made by the use of spider templets. Also called spider-templet plot. | HDBK-850 |
| spiral curve | (route surveying) A curve of uniformly varying radius connecting a circular curve and a tangent, or two circular curves whose radii are, respectively, longer and shorter than its own extreme radii. Also called easement curve; transition curve. | HDBK-850 |
| spiral to spiral (SS) | A common point between two spirals. | HDBK-850 |
| spirit level | A closed glass tube (vial) of circular cross section, its center line also forming a circular arc, its interior surface being ground to precise form; it is filled with ether or liquid of low viscosity enough free space being left for the formation of a bubble of air and gas. Also called bubble level. See also chambered spirit level; circular level; hanging level; latitude level; level trier; plate level; reversible level; rod level; striding level; telescope level. | HDBK-850 |
| spirit level axis | The line tangent to the surface of a spirit level tube (vial) against which the bubble forms, at the center of the graduated scale of the level, and in the plane of the longitudinal axis of the tube (vial) and its center of curvature. Also called axis of level; axis of the level bubble; bubble axis. | HDBK-850 |
| spirit level wind | Lack of parallelism between the axis of a spirit level vial and the line joining the centers of its supports. When wind (pronounced to rhyme with find) is present, the bubble will respond with a longitudinal movement when the spirit level is rocked on its supports. | HDBK-850 |
| spirit leveling | The determination of elevations of points with respect to each other or with respect to a common datum, by use of a leveling rod and an instrument using a spirit level to establish a horizontal line of sight. | HDBK-850 |
| split cameras | (JCS) An assembly of two cameras disposed at a fixed overlapping angle relative to each other. [Mainly used for reconnaissance purposes.] Also called split-vertical camera. | HDBK-850 |
| split photography | See split-vertical photography. | HDBK-850 |
| split-vertical camera | See split cameras. | HDBK-850 |
| split-vertical photography | (JCS) Photographs taken simultaneously by two cameras mounted at an angle from the vertical, one tilted to the left and one to the right, to obtain a small side overlap. Also called split photography. | HDBK-850 |
| spoking | (JCS) (radar) Periodic flashes of the rotating time base on a radial display. Sometimes caused by mutual interference. | HDBK-850 |
| spot cable | A free-text product that electronically transmits the results of imagery exploitation deemed by the reporting organization to be of such significance that immediate dissemination is warranted. | USIS 95 |
| spot elevation | (JCS) A point on a map or chart whose elevation is noted. [Elevations are shown, wherever practicable, for road forks and intersections, grade crossings, summits of hills, mountains, and mountain passes, water surfaces of lakes and ponds, stream forks, bottom elevations in depressions, and large flat areas.] Also called spot height. See also checked spot elevation; elevation; unchecked spot elevation. | HDBK-850 |
| spot height | See spot elevation. | HDBK-850 |
| spot prediction | A single heading radar prediction intended to portray, as nearly as possible, a comprehensive analysis of the radarscope at a precise geographic location. | HDBK-850 |
| spot size | (JCS) The size of the electron spot on the face of the cathode-ray tube. | HDBK-850 |
| spring balance | An accessory of taping and base measuring apparatus which is used in applying proper tension to a tape. | HDBK-850 |
| spur line of levels | A line of levels run as a branch from the main line of levels, either for the purpose of determining the elevations of marks not conveniently reached by the main line of levels or to connect with tidal bench marks or other previously established bench marks in obtaining checks on old leveling either at the beginning or end of a line of levels or at intermediate junctions along the new line of levels. | HDBK-850 |
| spur traverse | Any short traverse that branches off the established traverse to reach some vantage point or position. Also called stub traverse. | HDBK-850 |
| squint angle | Angle from the ground track to a position within the access butterfly. | USIS 95 |
| stabilized mount | A mount controlled by a gyroscope vertical reference unit designed to maintain a mapping or positional camera or other devices such as TPR antenna in a near vertical orientation independent of aircraft pitch and roll. | HDBK-850 |
| stable base | A general term applied to mapping materials possessing a high degree of dimensional stability. | HDBK-850 |
| stable gravimeter | A gravimeter having a single weight or spring such that the sensitivity is proportional to the square of its period. | HDBK-850 |
| stable-base film | (JCS) A particular type of film having high stability in regard to shrinkage and stretching. [Suitable for aerial mapping photography and map production. Usually referred to by its commercial name.] | HDBK-850 |
| stable-type gravimeter | A gravimeter which uses a high order of optical and/or mechanical magnification so that a change in position of a weight or associated property is measured directly. | HDBK-850 |
| stadia | A graduated rod used in the determination of distance by observing the intercept on the rod subtending a small known angle at the point of observation. In practice, the angle is usually defined by two fixed lines in the reticle of a telescope (transit or telescopic alidade). The term stadia is also used in connection with surveys where distances are determined with a stadia, as stadia survey, stadia method, stadia distance, etc.; also used to designate parts of the instrument used, as stadia wires. Also called stadia rod. See also horizontal stadia. | HDBK-850 |
| stadia circle | See Beaman arc. | HDBK-850 |
| stadia constant | (leveling) The ratio which is multiplied by the stadia interval to obtain the length of a sight in meters. Also, the ratio by which the sum of the stadia intervals of all sights of a run is converted to the length of the run in kilometers. | HDBK-850 |
| stadia diagram | A chart or drawing which provides a means for rapid field reduction of stadia readings. Usually it is prepared on cross-section paper and drawn to the scale of the survey being performed. | HDBK-850 |
| stadia intercept | See stadia interval. | HDBK-850 |
| stadia interval | (leveling) The length of rod subtended between the top and bottom cross hairs (cross wires) in the leveling instrument as seen projected against the face of the leveling rod. Also called stadia intercept. | HDBK-850 |
| stadia rod | See stadia. | HDBK-850 |
| stadia slide rule | The most rapid method of reducing stadia readings is by the use of a slide rule which has, in addition to the ordinary scale of numbers (logarithms of the distances), two scales especially constructed for stadia work, one consisting of values of log cos2 a and the other of log 1/2 sin 2 a for different values of a. On some rules, the values of a range from 0°34' to 45°; on others, from 0°03' to 45°. In some forms the horizontal distance is read directly; in others the horizontal correction (1-cos2) or sin2 is given. A 10-inch slide rule gives results sufficiently accurate for all ordinary purposes. | HDBK-850 |
| stadia traverse | A traverse in which distances are measured by the stadia method. | HDBK-850 |
| stadia trigonometric leveling | A technique of extending supplemental vertical control in areas of moderate or low relief. Distances are measured by stadia methods and can be done with planetable, transit, or theodolite. Field work is reduced to usable form by trigonometric computations. | HDBK-850 |
| stadimeter | An instrument for determining the distance to an object of known height by measuring the angle subtended at the observer by the object. The instrument is graduated directly in distance. See also range finder. | HDBK-850 |
| staff gage | The simplest form of tide or stream gage consisting of a graduated staff securely fastened to a pole or other suitable support. It is so designed that a segment of the staff will be below lowest low water when mounted and the remainder will be above water and positioned for direct observations from shore or some other vantage point. | HDBK-850 |
| stakeholder | An individual/organization that has a vested interest in DISA but may not necessarily be a customer. A Stakeholder may be a supplier or customer, internal or external. The common thread is that the Stakeholder can affect the process which produces products or services. [DISA QCS] | DISA CFS |
| Stampfer level | A type of leveling instrument having the telescope tube so mounted that it could be moved in a vertical plane about a horizontal axis, involving the use of a striding level and a micrometer screw. | HDBK-850 |
| standard | (JCS) An exact value, a physical entity, or an abstract concept, established and defined by authority, custom, or common consent to serve as a reference, model, or rule in measuring quantities or qualities, establishing practices or procedures, or evaluating results. A fixed quantity or quality. | HDBK-850 |
| standard | A document, established by consensus and approved by an accredited standards development organization, that provides, for common and repeated use, rules, guidelines, or characteristics for activities or their results, aimed at the achievement of the optimum degree of order and consistency in a given context. | IEEE P1003.0 |
| standard | A document that establishes uniform engineering and technical requirements for processes, procedures, practices, and methods. Standards may also establish requirements for selection, application, and design criteria of material. (DoD 4120.3-M) | JTA 2.0 |
| standard (IT) | IT standards provide technical definitions for information system processes, procedures, practices, operations, services, interfaces, connectivity, interoperability, information formats, information content, interchange and transmission/transfer. IT standards apply during the development, testing, fielding, enhancement, and life-cycle maintenance of DOD information systems. IT standards include non-government national or international standards, Federal standards, military standards, and multinational treaty organization standardization agreements. They may take numerous forms including standards, handbooks, manuals, specifications, commercial item descriptions, standardized drawings, all referred to collectively here as standards. [CJCSI 6212.01] | DISA CFS |
| Standard Automated Remote to AUTODIN Host (SARAH) | Air Force-developed software for personal computers to prepare and transmit DD-173 and JANAP-128 formatted messages via AUTODIN. [DISA/D2] | DISA CFS |
| standard automatic tide gage | A chronograph used where extended time readings of tidal changes are required. The rise and fall of the tide is communicated by a wire (attached to a float) to a worm screw on the gage, which moves a pen transferring the data to a permanent paper record. | HDBK-850 |
| standard corner | A senior corner on a standard parallel or base line. | HDBK-850 |
| standard development organization | An accredited organization that formally develops and coordinates standards for use by a community. | IEEE P1003.0 |
| standard deviation | See standard error. | HDBK-850 |
| standard error (s) | The square root of the variance. It implies a 68.27% probability that the parameter of observation has an error the absolute value of which does not exceed s. Also called standard deviation. | HDBK-850 |
| standard error of the mean | The standard error(s) of a most probable value established as the mean of n observations. It is rigorously derived as the standard error (s) of the n observations divided by the square root of n. It also has an implied probability of 68.27%. | HDBK-850 |
| standard feature | A function provided in a standard. Either a single facility or behavior, or, one of a pair of alternative facilities or behaviors, required by a standard that is always present on a conforming implementation. (IEEE Std. P1003.2-1991) | ITSG Vol. 1 |
| Standard General Pertutbations Satellite Orbit Model 4 (SGP4) | SGP4 is a standard general perturbations satellite orbit model developed for the U.S. Air Force in 1980. Orbital elements for SGP4 include epoch (t), eccentricity (e) mean motion (m), inclination (i), right ascension of node, argument of perigee, mean anomaly and some "drag" terms. | USIS 95 |
| Standard Generalized Markup Language (SGML) | An ISO standard for defining the formatting in a text document. | Multimedia |
| standard grids | The Universal Transverse Mercator (UTM) grid and the Universal Polar Stereographic (UPS) grid. | HDBK-850 |
| standard indexing system (SIS) | A system developed for use within the Department of Defense for the indexing of all aerial photography held at national level. Aerial photographic missions are plotted on acetate sheets covering 1° squares of the world at a scale of 1:250,000. | HDBK-850 |
| standard interchange format (SIF) | SIF is a format which allows data to be transferred among dissimilar computer systems. SQL stands for Structured Query Language, a relational database. | OpenGIS Guide |
| standard interval | The basis for measuring length of time on an interval time scale, normally one of the units specified by ISO 31-1. | ISO/TC 211 |
| standard linear format (SLF) | A standard format used and modified by NIMA for digital cartographic data. SLF uses a chain-node spatial structure to avoid duplication of common boundaries. | HDBK-850 |
| standard map | A map which complies with specific Map Accuracy Standards and guidelines. | HDBK-850 |
| standard meridian | 1. The meridian used for determining standard time. 2. A meridian of a map projection, along which the scale is as stated. | HDBK-850 |
| standard of length | A physical representation of a linear unit that is approved by competent authority. | HDBK-850 |
| standard parallel | 1. (JCS) A parallel on a map or chart along which the scale is as stated for that map or chart. 2. A parallel of latitude used in the computation of a map projection. | HDBK-850 |
| standard port | See reference station. | HDBK-850 |
| standard quadrangle | A quadrangle of a specific series, conforming with the systematic pattern of the series. | HDBK-850 |
| Standard Simulator Database Interchange Format (SIF) | A DoD data exchange standard (MIL-STD-1821) adopted as an input/output vehicle for sharing externally created simulator databases among the operational system training and mission rehearsal communities. | JTA 2.0 |
| standard station | See reference station. | HDBK-850 |
| standard survey | A survey which, in scale, accuracy, and content, satisfies criteria prescribed for such a survey by competent authority. | HDBK-850 |
| standard tension | (taping) That tension or pull at which a tape was standardized. | HDBK-850 |
| standard time | Mean solar time for a selected meridian adopted for use throughout a belt or zone. | HDBK-850 |
| standardization | The process of developing and agreeing upon (by consensus or decision) uniform engineering criteria for products, processes, practices, and methods. [DOD 4120.3-M] | DISA CFS |
| standardization areas | Standardization categories for engineering technologies, disciplines, and practices that do not fall under a Federal Supply Category (FSC) or Federal Supply Group (FSG). SD-1 identifies the Standardization Areas. [DOD 4120.3-M] | DISA CFS |
| Standardization Directory (SD-1) | A publication that identifies standardization responsibility assignments by FSCs, FSGs, and Standardization Areas. It also includes addresses, telephone numbers, and points of contact for the military offices, civilian agencies, and non-Government standards bodies participating in the Defense Standardization Program. [DOD 4120.3-M] | DISA CFS |
| standardization document | A generic term for a document used to standardize on an item of supply, process, procedure, method, data, practice, or engineering approach. Standardization documents include military specifications, standards, handbooks, and bulletins; federal specifications and standards; guide specifications; and NGSs. [DOD 4120.3-M] | DISA CFS |
| Standardization Management Activity (SMA) | A generic term to describe any DOD activity listed in SD-1 that functions as a Lead Standardization Activity, Preparing Activity, Participating Activity, Military Coordinating Activity, Custodian, Review Activity, Adopting Activity, or Item Reduction Activity. [DOD 4120.3-M] | DISA CFS |
| Standardization Program Plan | A document prepared by a LSA that identifies standardization opportunities, problems, and objectives, and establishes milestones for accomplishing standardization goals and specific tasks in a Federal Supply Category (FSC), Federal Supply Group (FSG), or standardization area. [DOD 4120.3-M] | DISA CFS |
| Standardization Project | A standardization effort approved by the cognizant LSA to develop, update, cancel, or adopt a standardization document, or conduct an item reduction study or engineering practice study. [DOD 4120.3-M] | DISA CFS |
| standardized profile | A balloted, formal, harmonized document that specifies a profile. | IEEE P1003.0 |
| standards based architecture | An architecture based on an acceptable set of standards governing the arrangement, interaction, and interdependence of the parts or elements that together may be used to form a [system], and whose purpose is to insure that a conformant system satisfies a specified set of requirements. (OS-JTF) | JTA 2.0 |
| standards profile | See profile, standards. | IEEE P1003.0 |
| Standards Profile Certification | Proof that a particular standard profile meets the specified tech | DISA CFS |
| standards reference model {TC 211} | A part of the ISO/TC 211 Reference Model that can be used to determine specific standards needs at the critical interfaces identified in the architectural reference model | ISO/TC 211 |
| standing requirement | A requirement that is continuing in value and is relatively stable in terms of the identity of the relevant targets and levels of collection and exploitation over an extended period of time. | USIS 95 |
| standing/standard operating procedure | A set of instructions covering those features of operations that lend themselves to a definite or standardized procedure without loss of effectiveness. The procedure is applicable unless ordered otherwise. | USIS 95 |
| star chart | A chart or map of the celestial sphere showing principal stars which are useful for observations for navigation or field astronomy. | HDBK-850 |
| star finder | A device to facilitate the recognition of stars, particularly for purposes of navigation and geodetic astronomy. | HDBK-850 |
| star trail | A streak-like image of a star recorded on a stellar plate by a photographic time exposure caused by the rotation of the Earth. | HDBK-850 |
| start node | (digital mapping) The first node of an edge (an edge is traversed from start node to end node). | HDBK-850 |
| starting control | Control available for the absolute orientation of the first plate pair along a line of flight for which control is to be extended. | HDBK-850 |
| state | A condition (e.g., the value of a particular feature attribute) that persists over a period of time. | ISO/TC 211 |
| state base map | A base map of the area of a state as the unit used as a base upon which data of a specialized nature are compiled or overprinted. | HDBK-850 |
| state coordinate systems | The plane rectangular coordinate systems established by the National Geodetic Survey, one for each state in the United States, for use in defining positions of geodetic stations in terms of plane rectangular (x and y) coordinates. Also called state system of plane coordinates. | HDBK-850 |
| state of an object | At a given instant in time, the condition of an object that determines the set of all sequences of actions in which the object can take part. | RM-ODP |
| State Plane Coordinate (SPC) System | A locational reference system developed in the 1930s which provides positional descriptions accurate to 1 foot in 10,000 within the United States. The SPC system divides the United States into 125 zones (5 cover Texas) and employs both Lambert conformal and Tranverse Mercator projections (depending upon a state's size and shape). Within any given SPC zone, X-Y coordinates are given in eastings and northings. A central meridian passes each zone and is given a false easting of 2 million feet. A false northing of 0 feet is established below the southern limit of each zone. | OpenGIS Guide |
| state system of plane coordinates | See state coordinate systems. | HDBK-850 |
| state vector | A set of parameters that define the position and velocity of an object at a specific time with respect to a reference system. | HDBK-850 |
| static gravity meter | A type of gravity instrument in which a linear or angular displacement is observed or nulled by an opposing force. | HDBK-850 |
| static invocation | Constructing a request at compile time. Calling an operation via a stub procedure. | CORBA 2.2 |
| static markings | (photogrammetry) Marks on photographic negatives or other sensor imagery caused by unwanted discharges of static electricity. | HDBK-850 |
| station | 1. (surveying) A definite point on the Earth whose location has been determined by surveying methods. It may or may not be marked on the ground. A station usually is defined by the addition of a term which describes its origin or purpose. Usually marked on the ground by a monument of special construction, or by a natural or artificial structure. 2. (route surveying) Any point whose position is given by its total distance from the starting hub; also, each stake set at 100-foot intervals along a route survey. See also A-station; air station; astronomic station; auxiliary station; B-station; base station; control station; data acquisition station; drift station; eccentric station; gravity reference stations; gravity station; ground station; horizontal control station; in-and-out station; intersection station; Laplace station; magnetic station; main scheme station; master station; oceanographic station; plus station; primary tide station; projector station; radio range station; reference station; resection station; satellite triangulation stations; secondary station; secondary tide station; setup; slave station; stream gaging station; subordinate station; subsidiary station; supplementary station; taping station; tide station; tracking station; traverse station; triangulation station. | HDBK-850 |
| station adjustment | The adjustment of angle measurements at a triangulation or traverse station to satisfy local requirements (such as horizon closure) without regard to observations or conditions at other points. Also called local adjustment. | HDBK-850 |
| station error | See deflection of the vertical. | HDBK-850 |
| station mark | A mark on the ground, either a monument of special construction, or a natural or artificial object, which pinpoints the location of a survey station. See also mark, definition 2. | HDBK-850 |
| station pointer | See three-arm protractor. | HDBK-850 |
| stationary field | Any natural field of force, as a gravimetric or magnetic field. | HDBK-850 |
| stationary orbit | An orbit in which the satellite revolves about the primary at the angular rate at which the primary rotates on its axis. From the primary, the satellite appears to be stationary over a point on the primary. See also synchronous satellite. | HDBK-850 |
| statoscope | A sensitive form of barometer used in aerial photography for measuring small differences in altitude between successive air stations. Usually recorded automatically on the film at the instant of exposure. See recording statoscope. | HDBK-850 |
| stellar aberration | The displacement of the observed position from the position where the body was geometrically located at the instant of observation due to the motion of the observing platform. | HDBK-850 |
| stellar camera | A camera for photographing the stars. | HDBK-850 |
| stellar magnitude | See magnitude, definition 1. | HDBK-850 |
| stellar map matching | A process during the flight of a vehicle by which a chart of the stars set into the guidance system is automatically matched with the position of the stars observed through telescopes so as to give guidance to the vehicle. See also map matching guidance. | HDBK-850 |
| stellar parallax | See annual parallax. | HDBK-850 |
| stellar plate | A precisely ground glass plate coated with a photographic emulsion used for recording satellite images against a stellar background. | HDBK-850 |
| step cast | The negative or positive reproduction of the stepped terrain base of a relief model. | HDBK-850 |
| step tablet | See step wedge. | HDBK-850 |
| step wedge | A strip of film or a glass plate whose transparency diminishes in graduated steps from one end to the other; often used to determine the density of a photograph. Also called gray scale; step tablet. See also continuous tone gray scale. | HDBK-850 |
| Stephenson leveling rod | A speaking rod having graduations forming a diagonal scale, with horizontal lines through the tenth-of-foot marks. This rod is read to hundredths of a foot. | HDBK-850 |
| steradian | The unit of measure of a solid angle. | HDBK-850 |
| stereo | 1. Contracted or short form of stereoscopic. 2. The orientation of photographs when properly positioned for stereoscopic viewing. Photographs so oriented are said to be "in stereo." | HDBK-850 |
| stereo | Two images taken of a single target on one imaging pass to allow three-dimensional viewing of a target. | USIS 95 |
| stereo oblique plotter | A device which permits continuous plotting of planimetric detail from oblique photographs. Essentially, the device consists of two photoangulators linked under a stereoscope and is provided with plotting arms. | HDBK-850 |
| stereo pair | See stereoscopic pair. | HDBK-850 |
| stereo- photogrammetry | Use of stereo images, such as overlapping photographs, in the science of photogrammetry. See also photogrammetry. | HDBK-850 |
| stereo triplet | A stereogram composed of three photographs, the center photo having a common field of view with the two adjacent photos, arranged in such a manner as to permit complete stereoscopic viewing of the center photograph. | HDBK-850 |
| stereocomparagraph | A relatively simple and mobile stereoscopic instrument used for the preparation of topographic maps from photography. Differences in elevation are determined by measuring parallax difference on a stereoscopic pair. | HDBK-850 |
| stereocomparator | A stereoscopic instrument for measuring parallax; usually includes a means of measuring photograph coordinates of image points. | HDBK-850 |
| stereocompilation | See compilation, definition 2. | HDBK-850 |
| stereogram | (JCS) A stereoscopic set (pair) of photographs or drawings correctly oriented and mounted (or projected) for stereoscopic viewing. See also stereo triplet. | HDBK-850 |
| stereograph | A stereometer with a pencil attachment which is used to plot topographic detail from a properly oriented stereogram. | HDBK-850 |
| stereographic chart | A chart on the stereographic projection. | HDBK-850 |
| stereographic coverage | The process of acquiring overlapping imagery coverage to allow a three-dimensional presentation of the scene; 60 percent overlap is considered normal and 53 percent generally is regarded as the minimum. | USIS 95 |
| stereographic horizon map projection | A stereographic projection having the center of the projection on some selected parallel of latitude other than the Equator. | HDBK-850 |
| stereographic map projection | A perspective, conformal map projection on a tangent plane, with the point of projection at the opposite end of the diameter of the sphere from the point of tangency of the plane. Also called azimuthal orthomorphic map projection. | HDBK-850 |
| stereographic meridional map projection | A stereographic projection having the center of the projection on the Equator. | HDBK-850 |
| stereometer | A measuring device containing a micrometer movement by means of which the separation of two index marks can be changed to measure parallax difference on a stereoscopic pair of photographs. Also called parallax bar. | HDBK-850 |
| stereometric camera | A combination of two cameras mounted with parallel optical axes on a short rigid base, used in terrestrial photogrammetry for taking photographs in steroscopic pairs. | HDBK-850 |
| stereometric map | See photogrammetric map. | HDBK-850 |
| stereomodel | See stereoscopic model. | HDBK-850 |
| stereomodel parameters | Numerical data for each image of a complete stereomodel or stereomodel section. The photo coordinates of an object imaged are related to the ground coordinates of the object by a projective relationship defined by a (sensor) mathematical model. | HDBK-850 |
| stereoplanigraph | A precise stereoscopic plotting instrument, especially valuable for extension of control, and capable of handling most types of stereoscopic photography, including terrestrial. | HDBK-850 |
| stereoscope | (JCS) A binocular optical instrument for helping an observer to view photographs or diagrams, to obtain a three-dimensional mental impression (stereoscopic model). [The design of stereoscopic viewing instruments utilizes lenses, mirrors, and prisms, or a combination thereof.] | HDBK-850 |
| stereoscopic | Of or pertaining to stereoscopy. | HDBK-850 |
| stereoscopic base | The distance and direction between complimentary image points on a stereoscopic pair of photographs. | HDBK-850 |
| stereoscopic cover | (JCS) Photo- graphs taken with sufficient overlap to permit complete stereoscopic examination. | HDBK-850 |
| stereoscopic exaggeration | See hyperstereoscopy. | HDBK-850 |
| stereoscopic fusion | The mental process which combines two perspective views to give a impression of a three-dimensional model. | HDBK-850 |
| stereoscopic image | See stereoscopic model. | HDBK-850 |
| stereoscopic model | (JCS) The mental impression of an area or object seen as being in three dimensions when viewed stereoscopically on photographs. Also called spatial model; stereomodel; stereoscopic image. | HDBK-850 |
| stereoscopic pair | (JCS) Two photographs [or images] with sufficient overlap of detail to make possible stereoscopic examination of an object or an area common to both. Also called stereo pair. | HDBK-850 |
| stereoscopic parallax | See absolute stereoscopic parallax. | HDBK-850 |
| stereoscopic plotting instrument | An instrument for compiling a map or obtaining spatial solutions by observation of stereoscopic models formed by stereoscopic pairs of photographs. See also double-projection direct-viewing stereoplotter; radial plotter: single-model instrument; stereo oblique plotter; stereocomparagraph; stereoplanigraph. | HDBK-850 |
| stereoscopic principle | The formation of a single, three-dimensional image by binocular vision of two photographic images of the same terrain taken from different exposure stations. | HDBK-850 |
| stereoscopic vision | The particular application of binocular vision which enables the observer to obtain the impression of depth, usually by means of two different perspectives of an object (as two photographs taken from different camera stations). | HDBK-850 |
| stereoscopy | The science which deals with three-dimensional effects and the methods by which they are produced. | HDBK-850 |
| stereotemplet | A composite slotted templet adjustable in scale and representative of the horizontal plot of a stereoscopic model. An assembly of stereotemplets provides a means of aerotriangulation for horizontal positions with a stereoscopic plotting instrument not designed for bridging. | HDBK-850 |
| stereotemplet triangulation | Aerotriangulation by means of stereotemplets. The method permits scale solutions by area and is not restricted to solutions along flight strips. | HDBK-850 |
| stereotopographic map | See photogrammetric map. | HDBK-850 |
| stereotriangulation | A triangulation procedure that uses a stereoscopic plotting instrument to obtain the successive orientations of the stereoscopic pairs of photographs into a continuous strip. The spatial solution for the extension of horizontal and/or vertical control using these strips (or flight) coordinates may be made by either graphical or computational procedures. Also called bridging; instrument phototriangulation; multiplex triangulation. See also vertical stereotriangulation. | HDBK-850 |
| stickup | Adhesive-backed or wax-backed film or paper which map names, symbols, descriptive terms, etc., have been printed, for application in map and chart production. | HDBK-850 |
| still frame | A term for a captured frame of motion video or, less often, a still graphic image of any type. Also used to describe conferencing systems restricted to this mode of transmission and display. | Multimedia |
| stilling device | Any device or structure placed in the vicinity of a gage to reduce wave action and afford more accurate reading of the gage. | HDBK-850 |
| stipple | A random dot pattern used to depict certain topographic features such as sand. | HDBK-850 |
| Stokes' formula | A formula for computing geoid heights from gravity data. | HDBK-850 |
| stone bound | A substantial stone post set into the ground with its top approximately flush with the ground surface to mark accurately and permanently the important corners of a land survey. | HDBK-850 |
| stop | See aperture stop. | HDBK-850 |
| stop numbers | See relative aperture. | HDBK-850 |
| storage tube display | A CRT display on which an image can be stored on the screen for several minutes or longer with a single pass of the electron beam. | HDBK-850 |
| Store-and-Forward Message System | The communication process that allows messages to be stored at intermediate nodes before being forwarded to their destination. X.400 defines a message handling system that uses this process. | TAFIM 3.0 |
| stovepipe system | A system, often dedicated or proprietary, that operates independently of other systems. The stovepipe system often has unique, nonstandard characteristics. | TAFIM 3.0 |
| straight line graver | A variation of the rigid tripod graver so designed that the scribing point, the vertical vane, and one supporting leg are all directly in line; used with a straightedge for scribing long, straight lines. | HDBK-850 |
| strategic intelligence | (DOD) Intelligence that is required for the formulation of military strategy, policy, and military plans and operations at national and theater levels. See also intelligence; operational intelligence (OPINTEL); tactical intelligence (TACINTEL). | JPUB 1-02 |
| strategic map | (JCS) A map of medium scale, or smaller, used for planning of operations, including the movement, concentration, and supply of troops. See also map. | HDBK-850 |
| strategic planning model | Small-scale terrain models depicting only the general character of the terrain and features of considerable prominence. They generally embrace continental areas, countries, extensive land mass areas, or principal island masses and are most frequently used in high echelon planning activities. | HDBK-850 |
| stratosphere | (JCS) The layer of the atmosphere above the troposphere in which the change of temperature with height is relatively small. See also atmosphere. | HDBK-850 |
| stratum | One of a series of layers, levels, or gradations in an ordered system. NOTE - the term is used in the sense of (1) a region of sea, atmosphere, or geology that is distinguished by natural or arbitrary limits; (2) a socioeconomic level of society comprised of persons of the same or similar status, especially with regard to education or culture; or (3) a layer of vegetation, usually of the same or similar height. | ISO/TC 211 |
| stream gaging station | A point along a stream at which periodic measurements of velocity or discharge are made, and at which daily or continuous records of the stage of height of the water surface above a given datum is obtained. | HDBK-850 |
| streaming | The displaying of data (usually audio or video) as it arrives rather than waiting for all the data to arrive before displaying it. | Multimedia |
| strength of figure | (triangulation) The comparative precision of computed lengths in a triangulation net as determined by the size of the angles, the number of conditions to be satisfied, and the distribution of base lines and points of fixed position. Strength of figure in triangulation is not based on an absolute scale but rather is an expression of relative strength. Also applicable to the individual geometric figures within a given net. | HDBK-850 |
| stretching apparatus | See tape stretcher. | HDBK-850 |
| striding level | A spirit level so mounted that it can be placed above and parallel with the horizontal axis of a surveying or astronomic instrument, and so supported that it can be used to measure the inclination of the horizontal axis to the plane of the horizon. | HDBK-850 |
| strip | See flight strip. | HDBK-850 |
| strip adjustment | Similar to a block adjustment, but limited to a single strip of photographs. | HDBK-850 |
| strip coordinates | The coordinates of any point in a strip. Whether on the ground or actually on air station, referred to the origin and axes of the coordinate system of the first overlap. | HDBK-850 |
| strip film | A photographic film in which the emulsion membrane can be removed from its temporary base after exposure and processing the membrane is then transferred to a new base. Principally used in correction work. Also called stripping film. | HDBK-850 |
| strip mosaic | A mosaic consisting of one strip of aerial photographs taken on a single flight. | HDBK-850 |
| strip plot | (JCS) A portion of a map or overlay on which a number of photographs taken along a flight line is delineated without defining the outlines of individual prints. | HDBK-850 |
| strip prediction | A single heading prediction intended to convey the general nature and pattern of radar returns continuously along a specific flight path. | HDBK-850 |
| strip radial plot | See strip radial triangulation. | HDBK-850 |
| strip radial triangulation | A direct radial triangulation in which the photographs are plotted in flight strips without reference to ground control and the strips are later adjusted together and to the ground control. Also called strip radial plot. | HDBK-850 |
| strip width | The average dimension, measured normal to the flight line, of a series of neat models in a flight strip. Strip width is generally considered as equal to width between flights. | HDBK-850 |
| stripping | The cutting, attachment, and other operations for assembling cut film sections to produce a flat. | HDBK-850 |
| stripping film | See strip film. | HDBK-850 |
| structure primitive | A description of the relative position of a feature. | ISO/TC 211 |
| structure primitive type | A class of structure primitives. | CEN/TC 287 |
| Structured Query Language (SQL) | Standard command language for accessing a relational database. [DISA/D2] | DISA CFS |
| stub | A local procedure corresponding to a single operation that invokes that operation when called. | CORBA 2.2 |
| stub | An engineering object in a channel that interprets the interactions conveyed by the channel, and performs any necessary transformations or monitoring based on this interpretation. Stubs are the engineering object in the channel which interface directly with the client and server objects. | RM-ODP |
| stub traverse | See spur traverse. | HDBK-850 |
| style sheet | A graphic guide for the format and portrayal of grid and marginal information. Also called mock-up. | HDBK-850 |
| subaqueous reconnaissance survey | A hydrographic survey which is a rapidly executed preliminary survey of a region to provide advance information to meet immediate military needs. Normally made at small scale, it is usually not controlled by triangulation, and may be little more than a sketch with only a few critical soundings shown. | HDBK-850 |
| subaqueous running survey | A hydrographic survey of an exploratory nature along an unknown or hostile coast made from shipboard to determine the general form of the coast and the nature of the area. | HDBK-850 |
| subastral point | See substellar point. | HDBK-850 |
| subdivision survey | A type of land survey in which the legal boundaries of an area are located and the area is divided into parcels of lots, streets, right-of-way, and other accessories. All necessary corners or dividing lines are marked or monumented. | HDBK-850 |
| Sub-Exploitation Problem Set | A group of targets within an exploitation problem set (EPS) that have common exploitation criteria (EEIs) that are all tasked as either national or departmental (direct support), and are all assigned to the same organization for exploitation. | USIS 95 |
| subgravity | A condition in which the resultant ambient acceleration is between zero and one g. | HDBK-850 |
| sublunar point | The geographical position of the Moon. That point of the Earth at which the Moon is in the zenith at a specified time. See also subsatellite point. | HDBK-850 |
| submarine relief | Variations in elevation of the ocean floor, or their representation by depth curves, tints, or soundings. | HDBK-850 |
| subnet | To implement a network addressing scheme for 802.3 networks which divides the network into smaller pieces or segments. This reduces network traffic and improves overall network performance. [DISA/DO3 (CIO)] | DISA CFS |
| subordinate station | 1. One of the places for which tide or tidal current predictions are determined by applying a correction to the predictions of a reference station. 2. A tide or tidal current station at which a short series of observations has been made, which are reduced by comparison with simultaneous observations at a reference station. | HDBK-850 |
| subsatellite point | The point at which a line from the satellite perpendicular to the ellipsoid intersects the surface of the Earth. See also sublunar point. | HDBK-850 |
| subsidiary station | A station established to overcome some local obstacle to the progress of a survey, and not to determine position data for the station point. The term subsidiary station is usually applied to A-stations of a traverse survey. Subsidiary stations usually are temporary in character and not permanently marked. If serving the additional purpose of supplying control for a local survey, such station may be permanently marked and it is then a supplementary station. | HDBK-850 |
| subsolar point | The geographical position of the Sun. That point on the Earth at which the Sun is in the zenith at a specified time. See also substellar point. | HDBK-850 |
| substellar point | The geographical position of a star. That point on the Earth at which the star is in the zenith at a specified time. Also called subastral point. See also subsolar point. | HDBK-850 |
| substitute center | A point which, because of its ease of identification on overlapping photographs, is used instead of the principal point as a radial center. | HDBK-850 |
| subsurface float | A hollow cylinder, with its axis held vertical, at a constant depth by the buoyant effect of an indicating surface float; used to determine current velocities in streams or channels having a relatively uniform depth. | HDBK-850 |
| subtense bar | A horizontally held bar of precisely determined length, used to measure distances by observing the angle it subtends at the distance to be measured. | HDBK-850 |
| subtense bar traverse | A traverse method in which course lengths are measured by use of a subtense bar. | HDBK-850 |
| subtense base traverse | A traverse method in which distances are determined by precisely measuring, at one end of the course, the angle subtended by a precisely measured base at the other end of the course and approximately normal to it. | HDBK-850 |
| subtense method | A procedure by which distance measurements are obtained by use of a subtense bar. | HDBK-850 |
| subtracting tape | A calibrated surveyor's tape with the first foot (or meter) at each end graduated in tenths or hundredths Also called cut tape. See also adding tape. | HDBK-850 |
| subtype | An entity is a of a subtype of a give type if and only if its properties satisfy the predicate of the given type, and other, subtype-specific predicates. | RM-ODP |
| subtype relationship | A relationship between two entities or two features where one is a specialization of the other. | ISO/TC 211 |
| Summary of Corrections | A summary of outstanding notices [i.e., Notices to Mariners] affecting all nautical charts and publications. This information is also accessible on the Navigation Information Network (NAVINFONET). | HDBK-850 |
| summer solstice | 1. That point on the ecliptic occupied by the Sun at maximum northerly declination. Also called first point of Cancer. 2. That instant at which the Sun reaches the point of maximum northerly declination, about June 21. | HDBK-850 |
| Sun | The luminous celestial body at the center of the solar system, around which the planets, planetoids, and comets revolve. It is an average star. See also apparent sun; dynamical mean sun; fictitious sun. | HDBK-850 |
| sun elevation angle | The sun elevation angle is the angle from the tangent plane at the ground point to the sun distance between the satellite and the ground point. | USIS 95 |
| sun synchronous | An Earth satellite orbit in which the orbital plane is near polar and the altitude such that the satellite passes over all places on Earth having the same latitude twice daily at the same local time. | HDBK-850 |
| sun-synchronous orbit | An orbit in which the orbit plane precesses at the same rate as the Earth rotates about the sun. The satellite passes over a point on the earth at approximately the same local time each day. | USIS 95 |
| Sun-zenith distance | The angle between the zenith and the Sun's disk. | HDBK-850 |
| super high frequency | The frequency spectrum from 3 GHz to 30 GHz. | USIS 95 |
| superfeature | Several feature components having the same, or similar, attribution that are joined together to create one feature. An example of a superfeature could be a railroad system consisting of all the railroad tracks, spurs, sidings, terminals, bridges, and culverts within that system. | HDBK-850 |
| superior conjunction | The conjunction of a planet and the Sun when the Sun is between the Earth and the other planet. | HDBK-850 |
| superior planets | The planets with orbits larger than that of the Earth; Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. | HDBK-850 |
| superior transit | See upper transit. | HDBK-850 |
| Superset {DII COE} | The total collection of all COE-based segments available to the development community. The superset includes the COE as well as mission-application segments. | DII COE IRTS |
| superwide-angle lens | A lens having an angle of coverage greater than 100°. A lens whose focal length is approximately less than one-half the diagonal of the format. Also called ultrawide-angle lens. | HDBK-850 |
| supplemental control | Points established by subordinate surveys, to relate aerial photographs used in mapping with the system of geodetic control. The points must be positively photoidentified, that is, the points on the ground must be positively correlated with their images on the photographs. | HDBK-850 |
| supplemental control point | A photoimage point for which an elevation or a horizontal position, or both, is to be, or has been determined. See also control point. | HDBK-850 |
| supplemental elevation | A point whose vertical position has been determined by photogrammetric methods and is intended for use in the orientation of other photographs. Also called vertical pass point. | HDBK-850 |
| Supplemental Photo Interpretation Report | A national target report or a DoD imagery interpretation report that contains imagery-derived information from second-phase exploitation of overhead imagery. Formerly called a Supplemental Phase Interpretation Report. | USIS 95 |
| supplemental photography | Non-cartographic aerial and terrestrial photography that is used to enhance specific characteristics of mapping and charting photographic products. Primarily, supplemental photography is obtained with a reconnaissance camera using a relatively long focal length to provide greater image detail than is available in photographs obtained with mapping cameras. | HDBK-850 |
| supplemental plat | A plat prepared entirely from office records designed to show a revised subdivision of one or more sections without change in the section boundaries and without other modification of the subsisting record. | HDBK-850 |
| supplemental position | A point whose horizontal position has been determined by photogrammetric methods and is intended for use in the orientation of other photographs. Also called horizontal pass point. | HDBK-850 |
| supplemental posts for survey monuments | See identification posts. | HDBK-850 |
| supplemental station | Those stations established only for supplemental vertical control. They normally are not permanently marked (some are merely photoidentified) and accuracy does not have to be of the same order as the horizontal control to which it is tied. Also called vertical-angle station. | HDBK-850 |
| supplementary bench mark | See temporary bench mark. | HDBK-850 |
| supplementary contour | A contour line between intermediate contour lines to increase the topographic expression of an area, usually in areas of extremely low relief. Also called auxiliary contour. | HDBK-850 |
| supplementary instructions | New information, amendments, or changes to specifications or compilation instructions affecting the production of a specific map or chart, or a series of maps or charts. | HDBK-850 |
| supplementary station | An auxiliary survey station, established to increase the number of control stations in a given area, or to place a station in a desired location where it is impracticable or unnecessary to establish a principal station. Supplementary stations are permanently marked, and are established with an accuracy and precision somewhat lower than is required for a principal station, since they do not serve as bases from which extensive surveys are run. Also called secondary station. | HDBK-850 |
| support cost estimates | A detailed description of the resources needed to provide the support required by this new item throughout the life cycle. All costs identified in this support cost estimate should conform to the cost breakout contained in the OSD Cost Analysis Improvement Group (CAIG) approved cost element structure (CES). This estimate will include the costs of acquiring and fielding a support structure, support in all of the ILS elements during the O & M phase of the life cycle, and the anticipated disposal of the system at the end of the life cycle. In all instances, this cost estimate must agree with the estimates from the Program Management Office (PMO) [DISA/D4] | DISA CFS |
| Support for the Analyst File Environments (SAFE) | SAFE-C is the CIA dedicated system high automatic data processing operating environment that provides access to previously published intelligence reports. SAFE-D is the DIA dedicated, SCI high, ADP operating environment permitting access to a data base of several years of intelligence documents (mostly messages and intelligence reports sent via message) and to current message traffic that can be selected according to a user's profile. | USIS 2-1.1 |
| Support for the Analysts' File Environment (SAFE) {CIA} | A CIA-dedicated system-high automatic data processing operating environment that provides access to previously published intelligence reports. | USIS 95 |
| Support for the Analysts' File Environment (SAFE) {DIA} | A DIA-dedicated, SCI-high, ADP operating environment that began development in 1982 and is available to DIA personnel and selected intelligence analysts at various Commands on personal computers netted together on local area networks. It permits access to a data base of several years of intelligence documents (mostly messages and intelligence reports sent via message) and to current message traffic that can be selected according to a user's profile. It also allows for the creation and storage of electronic documents that can be downloaded to a personal computer operating system such as DOS or UNIX and for conducting computations written in programming languages such as FORTRAN and BASIC. It is run on an IBM mainframe computer located in the DIAC. | USIS 95 |
| supported commander | The commander having primary responsibility for all aspects of a task assigned by the Joint Strategic Capabilities Plan (JSCP) or other joint operations planning authority. In the context of joint operation planning, this term refers to the commander who prepares OPLANS, CONPLANs, concept summaries and OPORDs in response to requirements of the CJCS. | USIS 95 |
| Supporting Arms Coordination Center (SACC) | Established by the Commander, Amphibious Task Force, this agency exercises overall coordination of supporting fires, to include artillery, naval gunfire, and air support. The SACC integrates the fire plans of supporting arms to ensure the most effective support for the Landing Force scheme of maneuver, until command and control are passed ashore. | USIS 95 |
| supporting commander | A commander who furnishes augmentation forces or other support to a supported commander or who develops a supporting plan. Includes the designated combatant commands and Defense agencies, as appropriate. | USIS 95 |
| Supporting Products {C4ISR AF} | These products provide data that will be needed depending on the purpose and objectives of a specific architecture effort. Appropriate products from the supporting product set will be developed depending on the purpose and objectives of the architecture. | C4ISR AF |
| Supreme Headquarters Allied Powers Europe (SHAPE) | The Supreme Allied Commander Europe (SACEUR) is the North Atlantic Treaty Organisation's (NATO's) senior military commander in Europe. SACEUR's headquarters is called Supreme Headquarters Allied Powers Europe (SHAPE) and is located near Mons, Belgium. SHAPE advises NATO on military matters and oversees all aspects of Allied Command Europe (ACE). SHAPE is the first international military HQ to have been established and maintained in peace rather than wartime to deter hostilities, plan and, if necessary, conduct military operations on behalf of the allies. SOCEUR is primarily responsible for coordinating the defense of his command which stretches from Norway in Northern Europe to the Mediterranean Sea in the South, and from the Atlantic in the West to the Caucasus Mountains in Turkey in the East. | SHAPE Web Site |
| supression of enemy air defenses | Activity that neutralizes, destroys, or temporarily degrades surface-based enemy air defenses by destructive and/or disruptive means. | USIS 95 |
| surface | A level of spatial measurement referring to a three-dimensional defined space, e.g. contours, isolines, bathymetry, etc. | HDBK-850 |
| surface | A generic term for a bounded, continuous, two-and-a-half-dimensional representation of a terrain-surface using connected areas. | ISO/TC 211 |
| surface | A two dimentional geometric-spatial-element. | USIGS/CDM-A |
| surface anomalies | Irregularities at the Earth's surface, in the weathering zone, or in near surface beds which interfere with geophysical measurements. | HDBK-850 |
| surface chart | See weather map. | HDBK-850 |
| Surface Configuration Model | Defines the geometric characteristics of the Earth's surface, exclusive of features which fall upon the surface; defined in terms of elevation, shape, roughness, slope, and aspect, with the later properties possibly derived from elevation. | OpenGIS Guide |
| surface corrections | Corrections of geophysical measurements for surface anomalies and ground elevations. | HDBK-850 |
| Surface Feature | An entity which lies on the Earth's surface or is referenced to the Earth's surface. | OpenGIS Guide |
| surface float | A device, specially designed or improved, used in hydrographic surveys to determine surface movement of a stream. | HDBK-850 |
| surprint | See overprint, definition 1. | HDBK-850 |
| surveillance | The systematic observation of aerospace, surface or subsurface areas, places, persons, or things, by visual, aural, electronic, photographic, or other means. | JPUB 1-02 |
| survey | 1. The act or operation of making measurements for determining the relative positions of points on, above, or beneath the Earth's surface. 2. The results of such operations. 3. An organization for making surveys. See also aerial survey; Airborne Control system; airborne electronic survey control; area survey; astronomic surveying; boundary survey; cadastral survey; city survey; compass survey; control survey; control survey classification; dependent resurvey; electronic survey; engineering survey; exploratory survey; field inspection; first-order work; geodetic survey; geoelectric survey; geographic survey; geologic survey; gravimetric survey; ground survey; hydrographic survey; independent resurvey; inventory survey; land survey; Iocation survey; magnetic survey; magnetometer survey; metes-and-bounds survey; mine survey; mineral survey: oceanographic survey; photogrammetric survey; photographic survey; plane survey; preliminary survey; reconnaissance survey; rectan-gular surveys; resurvey; route survey; satellite surveying; second-order work; standard survey; subaqueous recon-naissance survey; subaqueous running survey; subdivision survey; third-order work; topo-graphic survey; town-site survey; transit-and-stadia survey; trilinear surveying. | HDBK-850 |
| survey coordinates | See rectangular space coordinates. | HDBK-850 |
| survey net | 1. (horizontal control) Arcs of triangulation, sometimes with lines of traverse, connected to form a system of loops or circuits extending over an area. Also called horizontal control survey net; traverse net; triangulation net. See also triangulation system; trilateration net. 2. (vertical control) Lines of spirit leveling connected to form a system of loops or circuits extending over an area. Also called control net; framework of control; level net; net. See also area triangulation; U.S. control survey nets. | HDBK-850 |
| survey photography | See mapping photography. | HDBK-850 |
| survey signal | A natural or artificial object or structure whose horizontal and sometimes vertical position is obtained by surveying methods. Signals are given special designations according to the kind of survey in which they are determined, or which they may later serve. | HDBK-850 |
| survey tower | A structure designed for rapid construction and removal to raise the survey instrument and observer above obstructions such as trees and buildings to permit a line-of-sight as required in higher order triangulation, trilateration, or traverse. See also Bilby steel tower. | HDBK-850 |
| surveying accessories | Those surveying devices which assist in making measurements with a surveying instrument. | HDBK-850 |
| surveying altimeter | An aneroid barometer with a dial graduated to read feet or meters of altitude, used to determine approximate differences in elevation between points. | HDBK-850 |
| surveying camera | See mapping camera. | HDBK-850 |
| surveying instruments | Those surveying devices with which measurements are made. See also electronic distance-measuring equipment; leveling instrument; tachymeter; theodolite; transit. | HDBK-850 |
| surveying sextant | A sextant intended primarily for use in hydrographic surveying. Also called hydrographic sextant. See also marine sextant. | HDBK-850 |
| surveyor's arrow | See pin. | HDBK-850 |
| surveyor's chain | See Gunter's chain. | HDBK-850 |
| swath | A strip on the Earth's surface that represents a boundary of sensor accessibility. | USIS 95 |
| sweep bar | A heavy section of steel rail suspended at a predetemined depth by two vertical cables and towed by a vessel for precise determination of navigation obstructions during a hydrographic survey. | HDBK-850 |
| swing | 1. The rotation of a photograph in its own plane about its camera axis. 2. On trimetrogron obliques, the angle between the principal line and the y-axis, or the angle between the isometric parallel and the x-axis. See also relative swing. 3. The angle at the principal point of a photo measured clockwise from the positive y-axis to the principal line at the nadir point. 4. (triangulation) See eccentric reduction. | HDBK-850 |
| swing offset | The perpendicular distance from a point to a transit line found by holding the zero point of a tape at the given point and swinging the tape in an arc until the minimum (horizontal) distance is obtained. | HDBK-850 |
| swing-swing method | A technique for clearing y-parallax during relative orientation by applying identical swing (or y-motion) to both projectors of a pair at the same time. This method has the advantage of affecting y-parallax correction without the use of translational motions. | HDBK-850 |
| switched network | 1. A communications network, such as the public switched telephone network, in which any user may be connected to any other user through the use of message, circuit, or packet switching and control devices. 2. Any network providing switched communications service. | FED STD 1037C |
| swivel graver | A scribing instrument with a swivel mechanism that permits changes in direction of scribing. | HDBK-850 |
| symbol | A diagram, design, letter, character, or abbreviation placed on maps, charts, and other graphics which by convention, usage, or reference to a legend is understood to stand for or represent a specific characteristic or feature. | HDBK-850 |
| symbolization | The method of portraying topographic features onto a manuscript. The symbols used on the manuscript are either a point (dot), a line, or an area (a delimiting line closing upon itself). | HDBK-850 |
| symbolized graphic data (SGD) | A data set which contains attribution for graphic output. Data may include symbolization options such as point, line, area, pattern, orientation, color (hue, value, tone, and intensity), size, shape, and texture. | HDBK-850 |
| synchronization | Ensuring that two or more features are at a certain position at a certain time by changing their spatial or temporal attributes. | ISO/TC 211 |
| Synchronized Multimedia Integration Language (SMIL) | A new markup language being developed by the World Wide Web Consortium (W3C) that would enable Web developers to divide multimedia content into separate files and streams (audio, video, text, and images), send them to a user's computer individually, and then have them displayed together as if they were a single multimedia stream. The ability to separate out the static text and images should make the multimedia content much smaller so that it doesn't take as long to travel over the Internet. SMIL is based on the eXtensible Markup Language (XML). Rather than defining the actual formats used to represent multimedia data, it defines the commands that specify whether the various multimedia components should be played together or in sequence. | PC Webopaedia |
| synchronous (system) | A type of system in which the send and receive instruments are operating continuously at substantially the same frequency and are maintained in a desired phase relationship; a method of packing bits inside a block with regular synchronized timing, negating the need for sending start and stop bits between characters to achieve a higher data rate. [Joint Pub 6-02.1] | DISA CFS |
| Synchronous Optical Network (SONET) | Is a set of network interface standards aimed at enabling global network interconnection. Sonet is a digital hierarchy ideally suited to handling fiber-optic communication, at the same time allowing easy extraction of lower rate signals. | DII MP |
| synchronous request | A request where the client pauses to wait for completion of the request. Contrast with deferred synchronous request and one-way request. | CORBA 2.2 |
| synchronous satellite | An Earth satellite moving eastward in an equatorial, circular orbit at an altitude (approximately 35,900 kilometers) such that its period of revolution is exactly equal to (synchronous with) the rotational period of the Earth. Such a satellite will remain fixed over a point on the Earth's Equator. Also called fixed satellite; 24-hour satellite. See also stationary orbit. | HDBK-850 |
| synchronous transfer mode | In a Broadband Integrated Services Digital Network (B-ISDN), a proposed transport level technique in which time-division multiplexing and switching is to be used across the user's network interface. Compare with asynchronous transfer mode (ATM). | FED STD 1037C |
| synchronous transmission | Digital transmission in which the time interval between any two similar significant instants in the overall bit stream is always an integral number of unit intervals. Compare with asynchronous transmission. | FED STD 1037C |
| synodic period | The interval of time between any planetary configuration of a celestial body, with respect to the Sun, and the next successive same configuration of that body, as from inferior conjunction to inferior conjunction. | HDBK-850 |
| synodical month | The average period of revolution of the Moon about the Earth with respect to the Sun, approximately 29 1/2 days. Also called lunar month; lunation. | HDBK-850 |
| synoptic chart | See weather map. | HDBK-850 |
| synoptic coverage | Refers to the capability to cover two or more targets or areas on the same pass or on the same day with the objective of freezing objects or activity in place and time. | USIS 95 |
| Synthesized UHF Computer Controlled Equipment Subsystem | An Army radio designed for use with the Enhanced Tactical Users Terminal (ETUT) and the Tactical High Mobility Terminal (THMT). It provides one transmit channel and three receive channels, and is designed to communicate with selected airborne, terrestrial, and satellite systems. | USIS 95 |
| synthetic aperture radar (SAR) | An effective antenna is produced by storing and comparing the doppler signals received while the aircraft travels along its flight path. This synthetic antenna (or array) is many times longer than the physical antenna, thus sharpening the effective beam width and improving azimuth resolution. A synthetic aperture radar achieves azimuth resolution through computer operations on a set of coherently recorded signals such that the processor is able to function like a large antenna aperture in computer memory, thus realizing azimuth resolution improvement in proportion to aperture size. The SAR concept was introduced by C. Wiley (USA) in 1951. | CCRS Glossary |
| Synthetic Environment Data Representation and Interchange Specification (SEDRIS) | The specification encompasses a robust data model, data dictionary, and interchange format supported by read and write application programmer's interfaces (APIs), data viewers, a data model browser, and analytical verification and validation data model compliance tools. | JTA 2.0 |
| synthetic environments (SE) | Internetted simulations that represent activities at a high level of realism from simulations of theaters of war to factories and manufacturing processes. These environments may be created within a single computer or a vast distributed network connected by local and wide area networks and augmented by super-realistic special effects and accurate behavioral models. They allow visualization of and immersion into the environment being simulated. (DoD 5000.59-P, "Modeling and Simulation Master Plan," October 1995, authorized by DoD Directive 5000.59, January 4, 1994) (CJCSI 8510.01, Chairman of the Joint Chiefs of Staff Instruction 8510.01, "Joint Modeling and Simulation Management," February 17, 1995) | JTA 2.0 |
| system | A set of different elements so connected or related as to perform a unique function not performable by the elements alone. The most important and distinguishing characteristic of a system, therefore, is the relationships among the elements. | DII COE IRTS |
| system | A collection of components organized to accomplish a specific function or set of functions. [IEEE 610.12] | IEEE 610-1990 |
| system | 1. People, machines and methods organized to accomplish a set of specific functions. [FIPS PUB 11-3] 2. An integrated composite of people, products, and processes that provides a capability or satisfy a stated need or objective. [DoD 5000.2] | JTA 2.0 |
| system | Something of interest as a whole or as comprised of parts. Therefore a system may be referred to as an entity. A component of a system may itself be a system, in which case, it may be called a subsystem. For modeling purposes, the concept of a system is understood in its general, system-theoretic sense. The term "system" can refer to an information processing system but can also be applied more generally. | RM-ODP |
| System 9 | A geographic information system with a feature oriented data base and continuous mapping. Developed by Computervision. | HDBK-850 |
| system architecture description | A product which documents an architecture and consists of one or more architectural views. | IEEE 1471 |
| System Compliance {DII COE} | The degree to which a COE-derived system in total meets COE standards, specifications, and rules. System compliance is a composite measure of all segments in the system whether they are part of the COE, or are application segments. The measure also includes provisions for components that are not COE-derived (e.g., mainframe components). | DII COE IRTS |
| System Context Diagrams | A system interface description showing exactly one system and its interfaces. | NIMA/AR |
| system corrections | Corrections such as missing pixel filling or conversion of raw telemetry to sensor engineering data to be applied uniformly to sensor output. These corrections are usually applied at the sensor's receiving station. | OGC RFI |
| system documentation | All documentation provided with an implementation, except the conformance document. (IEEE P1003.1-1990) | ITSG Vol. 1 |
| System Interface Description | Identifies the interfaces between system nodes (internodal perspective), between systems (intranodal perspective), and between the components of a system (intrasystem perspective). | C4ISR AF |
| System Management Service {DoD TRM} | A service of the Platform entity of the TRM that provides for the administration of the overall information system. These services include the management of information, processors, networks, configurations, accounting, and performance. | TAFIM 3.0 |
| system model | A representation of the information types, directions of flow, production stages, and user interfaces for a system. | HDBK-850 |
| system of astronomic constants | An interrelated group of values constituting a model of the Earth and the motions which together with the theory of celestial mechanics serves for the calculation of ephemerides. | HDBK-850 |
| system response time | Amount of time that elapses between a command being given and its being executed by the computer. [HCI Style Guide] | DISA CFS |
| system software | Computer programs that control, monitor, or facilitate the use of an Automated Information System; for example, operating systems, programming languages, communications, input-output control, sorts, security packages, and other utility programs. Includes off-the-shelf application packages obtained from manufacturers and commercial vendors such as for word processing, spreadsheets, database management, graphics, and computer-aided design. [Joint Pub 6-02.1] | DISA CFS |
| System Under Test (SUT) | The computer hardware, software and communication network required to support the IUT [Implementation Under Test]. | ISO/TC 211 |
| systematic error | An error that occurs with the same sign, and often with a similar magnitude, in a number of consecutive or otherwise related observations. For example, when a base is measured with a wrongly calibrated tape, there will be systematic errors. In addition, random errors will occur. Repetition does little or nothing to reduce the ill effect of systematic errors, which are a most undesirable feature of any set of observations. Much of the care in making observations is directed toward eliminating or correcting systematic errors. Also called regular error. See also accumulative error. | HDBK-850 |
| systems architecture view | The systems architecture view is a description, including graphics, of systems and interconnections providing for, or supporting, warfighting functions. For a domain, the systems architecture view shows how multiple systems link and interoperate, and may describe the internal construction and operations of particular systems within the architecture. For the individual system, the systems architecture view includes the physical connection, location, and identification of the key nodes (including materiel item nodes), circuits, networks, warfighting platforms, etc., and specifies system and component performance parameters (e.g., mean time between failure, maintainability, availability). The systems architecture view associates physical resources and their performance attributes to the operational view and its requirements per standards defined in the technical architecture. | C4ISR AF |
| Systems Communications Description | Represents the specific communications systems pathways or networks and the details of their configurations through which the physical nodes and systems interface. | NIMA/AR |
| Systems2 Matrix | Relationships among systems in a given architecture: can be designed to show relationships of interest, e.g., system-type interfaces, planned vs. existing interfaces, etc. | C4ISR AF |
| syzygy | A point of the orbit of a planet or satellite at which it is in conjunction or opposition. The term is used chiefly in connection with the Moon, when it refers to the points occupied by the Moon at new and full phase. See also equinoctial colure; solstitial colure. | HDBK-850 |
Last Updated by Mark Owens 7 January 1999.