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| Term | Definition/Description | Source |
| B frame | Bi-directional or B frames (sometimes called B pictures) refer to part of the MPEG video compression process whereby both past and future pictures/frames are used as references. B frames typically result in the most compression. | Multimedia |
| Bache-Wurdem base-line measuring apparatus | A compensating base line measuring apparatus having a measuring element composed of a bar of iron and a bar of brass, each a little less than 6 meters in length, held together firmly at one end, with the free ends so connected by a compensating lever as to form a compensating apparatus. | HDBK-850 |
| back azimuth | 1. (geodetic surveying) If the azimuth of point B from point A is given on a reference sphere or ellipsoid, the back azimuth is the azimuth of point A from point B. Because of the convergence of the meridians, the forward and backward azimuths of a line do not differ by exactly 180°, except where A and B have the same geodetic longitude or where the geodetic latitudes of both points are 0°. 2. (plane surveying) When referred to a plane rectangular coordinate system, same as above except forward and backward azimuths differ by exactly 180°. See also azimuth, definition 1. | HDBK-850 |
| back bearing | 1. A bearing differing by 180°, or measured in the opposite direction from a given bearing. Also called reciprocal bearing. 2. The bearing at the opposite end of a line from the observer as measured from the true meridian at the opposite end of the line. The back bearing on all lines (other than north-south lines) are different from the bearing at the observer's station. They differ by the amount of convergency of the meridians between the two points. | HDBK-850 |
| back focal distance | See back focal length. | HDBK-850 |
| back focal length | The distance measured along the lens axis from the rear vertex of the lens to the plane of best average definition. Also called back focal distance; back focus. | HDBK-850 |
| back focus | See back focal length. | HDBK-850 |
| backsight | 1. A sight on a previously established survey point or line. 2. (traverse) A sight on a previously established survey point, which is not the closing sight of the traverse. 3. (leveling) A reading on a rod held on a point whose elevation has been previously determined and which is not the closing sight of a level circuit; any such rod reading used to determine height of instrument prior to making a foresight. Aiso called plus sight. | HDBK-850 |
| backstep | The method of determining the offsets for the bottom latitude of a projection by measuring the appropriate distances down from the top latitude of a chart. | HDBK-850 |
| backup | An image printed on the reverse side of a map sheet already printed on one side. Also the printing of such images. | HDBK-850 |
| backup data base | Each receive element has a subset of the overall system to be used during outages and emergencies. | USIS 95 |
| balancing a survey | Distributing corrections through any traverse to eliminate the error of closure, and to obtain an adjusted position for each traverse station. Also called traverse adjustment. See also compass rule; distance prorate rule; transit rule. | HDBK-850 |
| Baldridge Award | This award is named after the late Secretary of Commerce Malcolm Baldridge. The official Title is the Malcolm Baldridge Quality Award. The purpose of the award is to encourage organizations to examine their current state of quality and to become more involved in the movement towards continuous quality improvement. [DISA QCS] | DISA CFS |
| Baldwin solar chart | A chart designed for orienting a planetable by means of the Sun's shadow. | HDBK-850 |
| ballistic camera | A precision terrestrial camera, usually employing glass plates, used at night to photograph such objects as rockets, missiles, or satellites against a star background. Also called tracking camera. See also BC-4 camera. | HDBK-850 |
| Ballistic Missile Defense Organization (BMDO) | Within the Office of the Under Secretary of Defense for Acquisition and Technology (OSD A&T), BMDO is responsible for managing, directing, and executing the Ballistic Missile Defense (BMD) Program. DoD has assigned to BMDO the mission to develop for fielding, militarily effective defenses against ballistic missiles. To accomplish this mission, BMDO provides central BMD management, defines the system architecture and design, integrates requirements and technology, develops budgets and allocates resources, ensures integration with other U.S. and international defense capabilities, ensures systems are interoperable, and coordinates Theater Missile Defense with National Missile Defense programs and systems. BMDO is located in Arlington, VA. | USD A&T Web Site |
| Ballistic Missile Early Warning System | A line of radar systems in northern Canada to aid the defense of the continent. | USIS 95 |
| band | A channel. A range of wavelengths of electromagnetic radiation. | HDBK-850 |
| band interleaved by line | A specific implementation of a multivariate raster dataset. For each line in the raster, the values of each of the variables or bands are stored in sequence, before the set for the succeeding line. | HDBK-850 |
| band sequential | A specific implementation of a multivariate raster data set. The complete data array for each separate variable or band is stored independently of the other variables. | HDBK-850 |
| bandwidth | Amount of transmission capacity. The complete range of frequencies over which a circuit or electronic system can function with minimal signal loss, typically less than 3 dB. Bandwidth can be dedicated to one user or shared among many users. | Multimedia |
| bandwidth compression (BWC) | Denotes reduction of bits needed to represent a file prior to transmission to increase data flow. | USIS 95 |
| bar check | A method of field calibrating the sounding equipment used in hydrographic survey by suspending a bar or disc beneath the transducer at various depths. | HDBK-850 |
| bar scale | See graphic scale. | HDBK-850 |
| Barlow leveling rod | A speaking rod marked with triangles each 0.02 foot in height. | HDBK-850 |
| barometer | An instrument for measuring atmospheric pressure. See also aneroid barometer; cistern barometer; mercury barometer; siphon barometer. | HDBK-850 |
| barometric altimeter | An instrument that indicates elevation or height above sea level, or some other reference height, by measuring the weight of air above the instrument. Also called pressure altimeter; sensitive altimeter. See also aneroid altimeter. | HDBK-850 |
| barometric elevation | An elevation determined with a barometer or altimeter. | HDBK-850 |
| barometric hypsometry | The determination of elevations by means of either mercurial or aneroid barometers. | HDBK-850 |
| barometric leveling | A method of determining differences of elevation from differences of atmospheric pressure observed with a barometer or barometric altimeter. A type of indirect leveling. | HDBK-850 |
| barycenter | The center of mass of a system of masses; as the barycenter of the Earth-Moon system. | HDBK-850 |
| basal coplane | (photogrammetry) The condition of exposure of a pair of photographs in which the two photographs lie in a common plane parallel to the air base. If the air base is horizontal, the photographs are said to be exposed in horizontal coplane. | HDBK-850 |
| basal orientation | The establishment of the position of both ends of an air base with respect to a ground system of coordinates. In all, six elements are required. These are essentially the three-dimensional coordinates of each end of the base. In practice, however, it is also convenient to express these elements in one of two alternative ways: (1) The ground rectangular coordinates of one end of the base and the difference between these and the ground rectangular coordinates of the other end of the base. (2) The ground rectangular coordinates of one end of the base, the length of the base, and two elements of direction such as base direction and base tilt. | HDBK-850 |
| basal plane | See epipolar plane. | HDBK-850 |
| base apparatus | (surveying) Any apparatus designed for use in measuring with accuracy and precision the length of a base line in triangulation, or the length of a line in first- or second-order traverse. See also Bache-Wurdeman base-line measuring apparatus; compensating base-line measuring apparatus; duplex base-line measuring apparatus; Hassler base-line measuring apparatus; iced-bar apparatus; Jaderin wires (base apparatus); optical base-line measuring apparatus; Repsold base-line measuring apparatus; Schott base-line measuring apparatus. | HDBK-850 |
| base chart | See base map. | HDBK-850 |
| base color | The first color printed of a polychrome map to which succeeding colors are registered. | HDBK-850 |
| base construction line | The bottom line of a map projection, at right angles to the central meridian, along which other meridians are established. | HDBK-850 |
| base data | The basic level of map data on which other information is placed for purposes of comparison or geographical correlation. | HDBK-850 |
| base direction | The direction of the vertical plane containing the air base, which might be expressed as a bearing or an azimuth. See also basal orientation. | HDBK-850 |
| base document {OGC} | The working draft of the OpenGIS Specification, maintained by the Chairman of the OGC Technical Committee, which is the repository for working papers that have been submitted by Committee members. | OpenGIS Guide |
| base information definition | An information model that provides a common, logically consistent definition of the elements from the Open Geodata Model used within an OpenGIS® application environment. | OpenGIS Guide |
| base line | 1. (JCS) (surveying) A surveyed line established with more than usual care, to which surveys are referred for coordination and correlation. 2. (JCS) (photogrammetry) The line between the principal points of two consecutive vertical air photographs. It is usually measured on one photograph after the principal point of the other has been transferred. 3. (JCS) (triangulation) The side of one of a series of connected triangles, the length of which measured with prescribed accuracy and precision, and from which the lengths of the other triangle sides are obtained by computation. [Base lines in triangulation are classified according to the character of the work they are intended to control, and the instruments and methods used in their measurement are such that prescribed probable errors for each class are not exceeded. These probable errors, expressed in terms of the lengths, are as follows: first-order base line, 1/1,000,000; second-order base line, 1/500,000; third-order base line 1/250,000.] Also called triangulation base line. 4. (USPLS) A line which is extended east and west on a parallel of latitude from an initial point, and from which are initiated other lines for the cadastral survey of the public lands within the area covered by the principal meridian that runs through the same initial point. 5. (navigation) The line between two radio transmitting stations operating in conjunction for the determination of a line of position, as the two stations of a loran system. | HDBK-850 |
| base manuscript | See compilation manuscript. | HDBK-850 |
| base map | (JCS) A map or chart showing certain fundamental information, used as a base upon which additional data of specialized nature are compiled or overprinted. Also, a map containing all the information from which maps showing specialized information can be prepared. See also chart base; map. | HDBK-850 |
| base map | A map that provides the background upon which thematic data is overlaid and analyzed. As inputs into a GIS, the term base map is usually applied to those sources of information about relatively permanent, sometimes timeless, features including topography, pedology, geology, cadastral divisions, and political divisions. Within a GIS database, such information may become part of a land base to which other information is indexed and referenced. | Open GIS Guide |
| base net | A small net of triangles and quadrilaterals, starting from a measured base line, and connecting with a line of the main scheme of a triangulation net. | HDBK-850 |
| base sheet | A sheet of dimensionally stable material upon which the map projection and ground control are plotted, and upon which stereotriangulation or stereocompilation is performed. | HDBK-850 |
| base standard | An approved International Standard, Technical Report, ITU-T Recommendation, or National Standard. | IEEE P1003.0 |
| base standard profile | A profile, or listing, of applicable base standards. (see Profile of Standards) | ITSG Vol. 1 |
| base station | 1. (surveying) The point from which a survey begins. 2. (gravity) A geographic position whose absolute gravity value is known. In exploration, a reference station where quantities under investigations have known values or may be under repeated or continuous measurement in order to establish additional stations in relation to it. | HDBK-850 |
| Base Station Video Imaging Transmission System | A complete basestation for capturing, processing, viewing, and transmitting/receiving color images in a ruggedized, operational transit case. A member of the Digital Video Imagery Transmission System (DVITS) family of secondary imagery dissemination systems, manufactured by the Harris Corporation. | USIS 95 |
| base tape | A tape or band of metal or alloy, so designed and graduated and of such excellent workmanship that it is suitable for measuring lengths of lines (base lines) for controlling triangulation, and for measuring the lengths of first- and second-order traverse lines. | HDBK-850 |
| base tilt | The inclination of the air base with respect to the horizontal. See also basal orientation. | HDBK-850 |
| base-altitude ratio | The ratio between the air base length and the flight altitude of a stereoscopic pair of photographs. This ratio is referred to as the K-factor. More commonly called base-height ratio. Also indicated functionally as B/H. | HDBK-850 |
| base-height ratio | See base-altitude ratio. | HDBK-850 |
| baseline | A specification or product that has been formally reviewed and agreed upon, that thereafter serves as the basis for further development and that can be changed only through formal change control procedures or a type of procedure such as configuration management. [IEEE STD 610.12] | DISA CFS |
| baseline coverage | During peacetime, baseline coverage is considered the most important broad area coverage requirement. | USIS 95 |
| base-line extension | (navigation) The continuation of the base line in both directions beyond the transmitters of a pair of radio stations operating in conjunction for determination of a line of position. | HDBK-850 |
| base-line levels | A level line run along a base line to determine and establish the elevation of the base-line stations. | HDBK-850 |
| baseline requirements | Those requirements necessary to maintain intelligence or informational data bases and training activities. These requirements would also support the routine production of operational support products or routine support to mission planning systems or training simulator systems requiring imagery data bases. Examples of these requirements are updating Integrated data bases, routine update imagery for Cruise Missile Planning Cells, data base imagery for Mission Support Systems (MSS), and imagery archives for aircraft training simulators. | USIS 95 |
| base-line terminal stations | The monumented stations marking the end points of a base line. | HDBK-850 |
| basement contours | Contours on the surface of the basement complex or basic metamorphic and volcanic rocks underlying an area. | HDBK-850 |
| basic control | Horizontal and vertical control of third- or higher-order accuracy, determined in the field and permanently marked or monumented, that is required to control further surveys. | HDBK-850 |
| basic cover | (JCS) Coverage of any installation or area of a permanent nature with which later coverage can be compared to discover any changes that have taken place. See also comparative cover. | HDBK-850 |
| Basic Encyclopedia (BE) | A DoD-maintained, comprehensive listing of installations and facilities worldwide. It is the parent document for more specialized documents such as the Target Data Inventory. | USIS 95 |
| Basic Encyclopedia (BE) number | The primary 10-character identifier code for point targets. The first four characters must be the number of the World Aeronautic Chart in which the target is located as computed from geographic latitude and longitude coordinates. Installation point targets are assigned the basic 10 character BE number. Aim point targets are assigned temporary 10-character BE numbers; Key areas of interest and facility targets are assigned 10-character basic BE numbers and five-character numeric suffixes. | USIS 95 |
| Basic Imagery Interpretation Brief (BIIB) | A hardcopy reporting product that distributes a single target or topic report usually for the purpose of updating a Basic Imagery Interpretation Report (BIIR), but sometimes to provide detailed exploitation results on specific aspects of a problem that are not considered of sufficient magnitude to require a BIIR. | USIS 2-1.1 |
| Basic Imagery Interpretation Report (BIIR) | A hardcopy reporting product that distributes a single detailed target or topic report based on in depth exploitation and analysis. | USIS 2-1.1 |
| basic intelligence | 1. Factual, fundamental, and generally permanent information about all aspects of a nation's physical, social, economic, political, biographical, and cultural features that is used as a base for intelligence products in support of planning, policy making, and military operations. 2. General reference material for use in planning that pertains to the intentions, capabilities, vulnerabilities, and resources of other countries or potential operational theaters. 3. Intelligence, on any subject, that may be used as reference material for planning and in evaluating subsequent information. | USIS 95 |
| Basic Interoperability {DII COE} | A primitive level of interoperability characterized by peer-to-peer connected systems that allow basic exchange of homogenous data (e.g., email, formatted messages), and allows for basic collaboration. This level of interoperability is achievable by relatively simple interfacing techniques, and by use of standard office automation products that provide data import/export functions for handling data from another product. | DII COE IRTS |
| Basic Object Adapter (BOA) | A Basic Object Adapter is an object adapter specified by CORBA which must be provided by every ORB. An object adapter is the CORBA term given to the environment in which server applications run. An object adapter provides services such as: registration of servers; instantiation of objects at runtime and creation and management of object references; handling of incoming client calls; and dispatching of client requests to server objects. | CORBA 2.2 |
| Basic Target Graphic | A graphic developed by target material users and producers that replaced the Automated Tactical Target Graphic (ATTG) as standard target material. | USIS 95 |
| batch processing | Processing data or the accomplishment of jobs accumulated in advance in such a manner that each accumulation thus formed is processed or accomplished in the same computer run. [HCI Style Guide] | DISA CFS |
| bathygraphic | Descriptive of ocean depths. | HDBK-850 |
| bathymetric | Relating to the measurement of ocean depths. | HDBK-850 |
| Bathymetric Archive Data (BAD) | In the DMA [NIMA] Digital Production System, the Bathymetric Archive Data (BAD) layer includes all soundings from all the surveys taken. The sounding data in the BAD layer will eventually be extremely dense. Also included is accuracy and source data, such as the time the survey was taken, where it was taken, and how it was taken. | HDBK-850 |
| bathymetric chart | A topographic map of the floor of the ocean. | HDBK-850 |
| bathymetric contour | See depth contour. | HDBK-850 |
| Bathymetric Model Data (BMD) | In the DMA [NIMA] Digital Production System, soundings from the Bathymetric Archive Data layer are selected to form the Bathymetric Model Data (BMD) layer. The soundings in the BMD layer are the most critical of all the soundings taken. These soundings form the model of the ocean floor for the compilation of Nautical Charts. See also Bathymetric Archive Data. | HDBK-850 |
| Bathymetric Navigation Charts (BNC) | Charts depicting underwater topography in the form of bathymetric curves. BNCs portray detailed multibeam/swath bathymetry. BNC sheets conform to the basic worldwide index of Bottom Contour (BC) Charts for scale, coverage, and number determination. | HDBK-850 |
| Bathymetric Navigation Planning Charts (BNPC) | Charts depicting underwater topography in the form of bathymetric curves. BNPCs portray detailed multibeam/swath bathymetry collected in the Oceanographic Survey Program and the morphological interpretation of interswath data. BNPC sheets conform to the basic worldwide index of Bottom Contour (BC) Charts for scale, coverage, and number determination. Produced at various scales. | HDBK-850 |
| Bathymetric Recovery Area Charts (BRACs) | See Precise Bathymetric Navigation Zone Charts. | HDBK-850 |
| bathymetry | The science of determining and interpreting ocean depths and topography. | HDBK-850 |
| Battle Damage Assessment (BDA) | The timely and accurate estimate of damage resulting from the application of military force, either lethal or non-lethal, against a predetermined objective. BDA can be applied to the employment of all types of weapon systems (air, ground, naval, and special forces weapon systems) throughout the range of military operations. BDA is primarily an intelligence responsibility with required inputs and coordination from the operators. BDA is composed of physical damage assessment, functional damage assessment, and target system assessment. See Bomb Damage Assessment (BDA). | JPUB 1-02 |
| battle map | (JCS) A map showing ground features in sufficient detail for tactical use by all forces, usually at a scale of 1:25,000. See also map. | HDBK-850 |
| Battlefield Awareness Data Dissemination (BADD) | The Battlefield Awareness and Data Dissemination (BADD) demonstration will develop, install, and evaluate an operational system that allows commanders to design their own information system; delivers to Warfighters an accurate, timely, and consistent picture of the joint/coalition battlefield and provides access to key transmission mechanisms and worldwide data repositories. | DARPA/ISO Web Site |
| Battlefield Information Transmssion System (BITS) | A program to address the digital data load of the future battlefield by capitalizing on the use of emerging commercial systems, such as direct broadcast satellites and digital cellular telephones & commercial component technologies such as Digital Signal Processing (DSP) chips and Monolithic Microwave Integrated Circuits in military unique systems. | DII MP |
| baud | 1. A unit of modulation rate. Note: One baud corresponds to a rate of one unit interval per second, where the modulation rate is expressed as the reciprocal of the duration in seconds of the shortest unit interval. 2. A unit of signaling speed equal to the number of discrete signal conditions, variations, or events per second. Note 1: If the duration of the unit interval is 20 milliseconds, the signaling speed is 50 bauds. If the signal transmitted during each unit interval can take on any one of n discrete states, the bit rate is equal to the rate in bauds times log2n . The technique used to encode the allowable signal states may be any combination of amplitude, frequency, or phase modulation, but it cannot use a further time-division multiplexing technique to subdivide the unit intervals into multiple subintervals. In some signaling systems, non-information-carrying signals may be inserted to facilitate synchronization; e.g., in certain forms of binary modulation coding, there is a forced inversion of the signal state at the center of the bit interval. In these cases, the synchronization signals are included in the calculation of the rate in bauds but not in the computation of bit rate. Note 2: Baud is sometimes used as a synonym for bit-per-second . This usage is deprecated (dissapproved of). | FED STD 1037C |
| BC-4 camera | A trade name for the ballistic or geodetic stellar camera consisting of a Wild Astrotar or Wild Cosmotar lens cone mounted on the modified lower part of the Wild T-4 astronomic theodolite. Originally designed for the recording of the trajectory of a rocket but since adapted for the photographic tracking of artificial Earth satellites for geodetic purposes. | HDBK-850 |
| beacon tracking | The tracking of a moving object by means of signals emitted from a transmitter or transponder within or attached to the object. | HDBK-850 |
| beam of light | A group of pencils of light, as those originating at the many points of an illuminated surface. A beam of parallel light rays is a special case in which each pencil is of such small cross section that it may be regarded as a ray. | HDBK-850 |
| Beaman arc | A specially graduated arc fitted to the vertical circle of a transit or alidade for the easy reduction of stadia observations. Also called stadia circle. | HDBK-850 |
| bearing | 1. (JCS) (general) The horizontal angle at a given point measured clockwise from a specific datum to a second point. Also called bearing angle. See also grid bearing; relative bearing. 2. (navigation) The horizontal direction of one terrestrial point from another, expressed as the angular distance from a reference direction. It is usually measured from 0° at the reference direction clockwise through 360°. The terms bearing and azimuth are sometimes used interchangeably, but in navigation the former customarily applies to terrestrial objects and the latter to the direction of a point on the celestial sphere from a point on the Earth. 3. (surveying) See bearing of line. See also astronomic bearing; back bearing; compass bearing; computed bearing; curve of equal bearing; electronic bearing; false bearing; great-circle bearing; grid bearing; Lambert bearing; magnetic bearing; polar bearing; rhumb bearing; true bearing. | HDBK-850 |
| bearing angle | See bearing, definition 1. | HDBK-850 |
| bearing bar | See azimuth instrument. | HDBK-850 |
| bearing circle | A ring designed to fit snugly over a compass or compass repeater, and provided with vanes for observing compass bearings. | HDBK-850 |
| bearing line | A line extending in the direction of a bearing. | HDBK-850 |
| bearing of line | (plane surveying) The horizontal angle which a line makes with the meridian of reference adjacent to the quadrant in which the line lies. A bearing is identified by naming the end of the meridian (north or south) from which it is reckoned and the direction (east or west) of that reckoning. Thus, a line in the northeast quadrant making an angle of 50° with the meridian will have a bearing of N 50° E. In most survey work, it is preferable to use azimuths rather than bearings. | HDBK-850 |
| bearing tree | A marked tree used as a corner accessory; its distance and direction from the corner being recorded. Bearing trees are identified by prescribed marks cut into their trunks; the species and sizes of the trees are also recorded. | HDBK-850 |
| behavior | The observable effects of an object performing the requested operation including its results binding . See language binding, dynamic invocation, static invocation, or method resolution for alternatives. | CORBA 2.2 |
| behavior of an object | A collection of actions with a set of constraints on when they may occur. The specification language in use determines the constraints which may be expressed. Constraints may include for example sequentiality, non-determinism, concurrency or real-time constraints. A behavior may include internal actions. The actions that actually take place are restricted by the environment in which the object is placed. | RM-ODP |
| behavioral view | The behavioral viewpoint describes what the system does. This viewpoint describes the flow of data into and out of the system and operations performed on that data. | IEEE 1471 |
| Bell gravity meter | A single-axis, pendulous force rebalance accelerometer mounted on a stabilized platform and interfaced to a dynamic digital filter for measuring gravity aboard a survey platform. | HDBK-850 |
| bench mark (BM) | A marked vertical control point which has been located on a relatively permanent material object, natural or artificial, and whose elevation above or below an adopted datum has been established. It is usually monumented to include bench mark name or number, frequently its elevation, and the name of the responsible agency. Since elevations are computed at a later time, they are seldom added to newer control bench marks. A BM (aside from a vertical angle bench mark) seldom has a surveyed latitude or longitude. See also first-order bench mark; junction bench mark; permanent bench mark; primary bench mark; second-order bench mark; temporary bench mark; tidal bench mark; vertical-angle bench mark. | HDBK-850 |
| Bessel spheroid (ellipsoid) | A reference ellipsoid having the following approximate dimensions: semimajor axis - 6,377,397.2 meters; semiminor axis - 6,356,078.9 meters; and the flattening or ellipticity - 1/299.15. | HDBK-850 |
| Besselian star numbers | Constants used in the reduction of a mean position of a star to an apparent position (used to account for short-term variations in the precession, nutation, aberration, and parallax). | HDBK-850 |
| Besselian year | See fictitious year. | HDBK-850 |
| Bessel's method | See triangle-of-error method. | HDBK-850 |
| best fit ephemeris | Location data that best satisfies a collection requirement (i.e., actual platform position). | USIS 95 |
| biangle screen | A photographic negative containing a composite of two dot screens, with the screen angles oriented 30° apart. These screens are used to print tones of color for chart features with thin lines. | HDBK-850 |
| bidimensional datum; 2-dimensional datum | Any datum which serves as a reference for defining 2-dimensional coordinates. EXAMPLE: horizontal datum. | CEN/TC 287 |
| Bilby steel tower | A triangulation tower consisting of two steel tripods, one within the other. The inner tripod holds the instrument platform, and the outer tripod holds the observer's platform. The tower can be easily erected and as easily disassembled and moved to a new location. See also survey tower. | HDBK-850 |
| bimargin format | The format of a map or chart on which the cartographic detail is extended to two edges of the sheet, normally north and east, thus leaving only two margins. See also bleed; bleeding edge. | HDBK-850 |
| binary digit (bit) | 1. A character used to represent one of the two digits in the numeration system with a base of two, and only two, possible states of a physical entity or system. 2. In binary notation either of the characters 0 or 1. 3. A unit of information equal to one binary decision or the designation of one of two possible and equally likely states of anything used to store or convey information. | FED STD 1037C |
| binder | An engineering object in a channel that instantiates and maintains a distributed binding between interacting engineering objects. | RM-ODP |
| binocular | An optical instrument for use with both eyes simultaneously. | HDBK-850 |
| binocular vision | Simultaneous vision with both eyes. | HDBK-850 |
| bisynchronous | A set of operating procedures originated by International Business Machines (IBM) for the synchronous transmission of binary coded data. [DISA/D2] | DISA CFS |
| bit | See binary digit (bit). | FED STD 1037C |
| bit error rate | The number of erroneous bits divided by the total number of bits transmitted, received, or processed over some stipulated period of time. | USIS 95 |
| bit map | A pattern of bits within a grid, stored in memory, and used to generate an image on a raster scan display. | HDBK-850 |
| bit plane | A gridded memory in a graphics device used for storing information for display. Typically one color is assigned to each bit plane for display. | HDBK-850 |
| bitmap | A pixel-by-pixel description of an image. Each pixel is a separate element. Also referred to as a raster image. | Multimedia |
| bits per second (b/s) | A unit used to express the number of bits passing a designated point per second. Note 1: For example, for two-condition serial transmission in a single channel in which each significant condition represents a bit, i.e., a 0 or a 1, the bit rate in bits per second and the baud have the same numerical value only if each bit occurs in a unit interval. In this case, the data signaling rate in bits per second is 1/T, where T is the unit interval. Note 2: The abbreviation "bps" is not in accordance with international standards, and is therefore deprecated. | FED STD 1037C |
| bivariate normal distribution function | Mathematical function describing the behavior of two-dimensional random errors (e.g., latitude, longitude; x, y; easting, northing). Also called circular normal distribution. | HDBK-850 |
| blackbody | An ideal surface or body that completely absorbs all radiant energy falling upon it. Blackbodies are used as models in the design and calibration of remote sensing systems. | HDBK-850 |
| blaze | A mark made upon a tree trunk usually at about breast height. The bark and a small amount of the live wood are removed with an axe or other cutting tool, leaving a flat, smoothed surface which forever brands the tree. On rough-barked tree monuments or bearing trees the appropriate marks are scribed into a smooth, narrow, vertical blaze the lower end of which is about 6 inches above the root crown. The blaze should be just long enough to allow the markings to be made. | HDBK-850 |
| bleed | 1. (lithography) A condition wherein ink pigment is dissolved by press fountain solution causing a light film of ink (scum) on the plate and impression. 2. (cartography) Cartographic detail extending to the edge of a map or chart sheet. | HDBK-850 |
| bleeding edge | (JCS) That edge of a map or chart on which cartographic detail is extended beyond the neatline to the edge of the sheet. See also bimargin format; bleed. | HDBK-850 |
| blind image | See blue line. | HDBK-850 |
| blip | (JCS) The display of a received pulse on a cathode-ray tube. Also called echo. | HDBK-850 |
| blister | See border break. | HDBK-850 |
| blitz | A collection strategy that concentrates imagery collection resources over a target or set of targets for a limited period of time. | USIS 95 |
| block | 1. (digital storage) A group of records or words treated as a logical unit of information. For example, a VAX magnetic disk block equals 512 bytes, and an unspecified magnetic tape block equals 8192 bytes. A fixed or variable number of records. 2. Synonymous with physical records-a sequence of words or characters written contiguously by a computer on an external storage medium. Typically, one block is written each time a WRITE command is executed. 3. A set of entities in a CAD system which can be treated as a single compound object. 4. (aerial photography) Two or more strips of overlapping photography. See also flight block. | HDBK-850 |
| block adjustment | The adjustment of strip coordinates or photograph coordinates for two or more strips of photographs. See also strip adjustment. | HDBK-850 |
| block out | See opaque, definition 3 or 4. | HDBK-850 |
| bloomed lens | See coated lens. | HDBK-850 |
| blooming | 1. The term used to describe localized overexposure caused by incoming radiant energy levels which exceed film emulsion latitude thereby causing the image to lack definition. 2. A process for increasing the light transmission of lenses. | HDBK-850 |
| blow up | A photographic enlargement. Also used as a verb. | HDBK-850 |
| blue line | A nonreproducible blue image or outline usually printed photographically on paper or plastic sheeting, and used as a guide for drafting, stripping, or layout. Also called blind image. | HDBK-850 |
| blue magnetism | The magnetism displayed by the south-seeking end of a freely suspended magnet. This is the magnetism of the Earth's north magnetic pole. See also red magnetism. | HDBK-850 |
| blunder | A mistake generally caused by carelessness. A blunder may be large and easily detectable, or smaller and more dangerous, or very small and indistinguishable from a random error. Blunders are detected by repetition and by external checks, such as closing a traverse or substituting the solution of an equation in the original. See also random error; systematic error. | HDBK-850 |
| boat sheet | The worksheet used in the field for plotting details of a hydrographic survey as it progresses. See also field sheet. | HDBK-850 |
| Bomb Damage Assessment (BDA) | The determination of the effect of all attacks on targets (e.g., bombs, rockets, or strafing). The preferred term is battle damage assessment. | USIS 95 |
| Bonne map projection | A modified equal-area map projection of the so-called conical type having lines representing a standard parallel and a central meridian intersecting near the center of the map. The line representing the central meridian (geographic) is straight and the scale along it is exact. All geographic parallels are represented by arcs of concentric circles at their true distances apart, divided to exact scale, and all meridians, except the central one, are curved lines connecting corresponding points on the parallels. | HDBK-850 |
| Boolean logic | A system of logical combinatorial variables linking two or more statements or conditions. Requirements Management System (RMS) recognizes the Boolean operators "AND," "OR," and "NOT," that may be used to link conditions within a Conditional Tasking Rule (CT) to define when and how a CT Rule response is triggered. RMS also uses Boolean operators and logic in defining standing production and distribution requirements. | USIS 95 |
| Boolean operation | Any operation in which each of the operands and the result take one of two values. | HDBK-850 |
| border break | (JCS) A cartographic technique used when it is required to extend a portion of the cartographic detail of a map or chart beyond the sheet lines into the margin. Also called blister. | HDBK-850 |
| border data | See marginal data. | HDBK-850 |
| border information | See marginal data. | HDBK-850 |
| border matching | The process by which individual digital data sets are joined together through merging/smoothing utilizing computer applications software. | HDBK-850 |
| Boston leveling rod | A two-piece rod with fixed target on one end. The target is adjusted in elevation by moving one part of the rod on the other. Read by vernier. For heights greater than 5 1/2 feet, the target end is up; for lesser heights, the target end is down. | HDBK-850 |
| Bottom Contour Charts (BC) | Charts depicting detailed underwater topography in the form of bathymetric curves. BCs provide a general picture of the seafloor and its features, portrayed from survey data and foreign published charts. Designed for the use of submarines or ships by the method of bottom contour matching. | HDBK-850 |
| Bouguer anomaly | A difference between an observed value of gravity and a theoretical value at the point of observation, which has been corrected for the effect of topography and elevation only, the topography being considered as a plate of indefinite extent. | HDBK-850 |
| Bouguer correction | A correction made in gravity work to take account of the altitude (elevation) of the station and the density of the mass between an infinite plane though the point of observation and the infinite plane of the reference elevation. | HDBK-850 |
| Bouguer plate | An imaginary layer of infinite length and of thickness equal to the height of the observation point above the reference surface (usually the geoid). In applying the Bouguer correction, the attracting layer lessens the free air effect. | HDBK-850 |
| Bouguer reduction | Geophysically, the Bouguer reduction removes all masses above the reference surface (usually the geoid) and then reduces the gravity from the terrain to the reference surface. | HDBK-850 |
| boundary | A closed 1-dimensional non-intersecting element delimiting an area. | ISO/TC 211 |
| boundary (de facto) | An international or administrative boundary whose existence and legality are not recognized by all concerned, or are not defined by appropriate documents, but which is a practical division between separate national or provincial administering authorities. | HDBK-850 |
| boundary (de jure) | An international or administrative boundary whose existence and legality are recognized. | HDBK-850 |
| boundary discontinuities | Different elevation values for common standard digital terrain elevation data (DTED) matrix points in adjacent data files. | HDBK-850 |
| boundary line | A line of demarcation between contiguous political or geographical entities. The word "boundary" is some times omitted, as in "state line"; some times the word "line" is omitted, as in "international boundary," "county boundary," etc. The term boundary line is usually applied to boundaries between political territories, and "state boundary line," between two states. A boundary line between privately owned parcels of land is termed a property line by preference, or if a line of the United States public land surveys, is given the particular designation of that survey system, as "section line," "township line," etc. | HDBK-850 |
| boundary map | A map prepared specifically for the purpose of delineating a boundary line and adjacent territory. | HDBK-850 |
| boundary monument | A material object placed on or near a boundary line to preserve and identify the location of the boundary line on the ground. | HDBK-850 |
| boundary point averaging | Averaging the elevations of common points from two different data sets and reassigning each the average value; or resolving a discrepancy between two elevations for a common point by assigning the average elevation value to that point. | HDBK-850 |
| boundary point weighted averaging | Resolving a discrepancy between a series of overlapping elevations from two data sets by biasing one data set utilizing either the accuracy of a data set or the relative distance to the edge of the data. | HDBK-850 |
| boundary survey | A survey made to establish or to reestablish a boundary line on the ground or to obtain data for constructing a map or plat showing a boundary line. The term boundary survey is usually restricted to surveys of boundary lines between political territories. For the survey of a boundary line between privately owned parcels of land, the term land survey is preferred; except in United States public land surveys the term cadastral survey is used. | HDBK-850 |
| boundary vista | A lane cleared along a boundary line passing through a wooded area. | HDBK-850 |
| bounding area | An area covered by a dataset . | CEN/TC 287 |
| bounding XY | The minimum and maximum planar co-ordinates which can be found in a dataset . | CEN/TC 287 |
| Bowie effect | The indirect effect on gravity due to the warping of the geoid, or the elevation of the geoid with respect to the spheroid of reference. | HDBK-850 |
| Bowie method of adjustment | A method for the adjustment of large networks of triangulation. | HDBK-850 |
| box compass | See declinatoire. | HDBK-850 |
| break angle | The deflection angle between the two vertical phases passing through the common nadir point and the principal points of the left and right oblique photographs. | HDBK-850 |
| break tape | See broken tape measurement. | HDBK-850 |
| breakaway method | See breakaway strip method. | HDBK-850 |
| breakaway strip method | A technique used in photomosaicking when two or more sheets are prepared. The process involves placing an extra wide strip of masking tape along the outside edge of the neatline of one sheet before mosaicking photos. The mosaicked overedge is then cut along the neatline and transferred to the adjoining sheet. Also called breakaway method. | HDBK-850 |
| break-circuit chronometer | A chronometer equipped with a device which automatically breaks an electric circuit, the breaks being recorded on a chronograph. | HDBK-850 |
| breaking tape | See broken tape measurement. | HDBK-850 |
| break-up | (JCS) 1. In detection by radar, the separation of one solid return into a number of individual returns which correspond to the various objects or structure groupings. This separation is contingent upon a number of factors including range, beam width, gain setting, object size, and distance between objects. 2. In imagery interpretation, the result of magnification or enlargement which causes the imaged item to lose its identity and the resultant presentation to become a random series of tonal impressions. | HDBK-850 |
| bridge | An electronic device which mixes the signals from three or more locations (e.g., for audio or audiographic teleconferencing). | Multimedia |
| bridge | The hardware and software used to connect circuits and equipment in two networks with the same protocol. | TAFIM 3.0 |
| bridging | A photogrammetric method of establishing and adjusting control between bands of existing ground control, both horizontally and vertically. The term is usually qualified as horizontal or vertical according to its primary purpose. Also called horizontal bridging; horizontal/vertical bridging; vertical bridging. | HDBK-850 |
| briefing board | Usually an annotated imagery graphic with one or more pages of amplifying text. Topic is usually a high current interest imagery target. | USIS 95 |
| brightness scale | (photography) The ratio of the brightness of highlights to the deepest shadow in the actual terrain, as measured from the camera stations, for the field of view under consideration . | HDBK-850 |
| brightness value | The amount of reflected or emitted energy exiting from the earth's surface as recorded by a remote sensing system. These data are stored as digital values on computer-compatible tapes (CCT) for digital image processing purposes. The greater the brightness of the scene (or return from the scene), the higher the digital value. Hence the values stored on the CCT are often referred to as brightness values. It is not proper to call them reflectance values unless the brightness values have been scaled to truly represent reflectance values. | HDBK-850 |
| British grid reference system | A system of rectangular coordinates devised or adopted by the British for use on military maps. There is no related global plan for the many grids, belts, and zones which make up the British grid system. It is being replaced by the Universal Transverse Mercator (UTM) grid system. | HDBK-850 |
| British Thermal Unit (BTU) | The energy required to raise the temperature of one pound of water one degree Fahrenheit. | USIS 95 |
| Broad Area Coverage | Addresses specific intelligence problems that require collection of large geographic areas-greater than 10,000 square nautical miles (SNM) and often tens of thousands of SNM in size-in a synoptic and contiguous fashion. | USIS 95 |
| broad area search reform | BAS reform is a better tailored BAS collection effort in response to needs for improved performance of BAS. BAS reform can be either an ad hoc or a standing requirement with high priority and a higher National Imagery Interpretation Rating Scale (NIIRS) value than before. | USIS 95 |
| Broadband | Refers to networks capable of delivering high bandwidth i.e., many bits per second. | Multimedia |
| Broadband Integrated Services Digital Network (B-ISDN) | Is defined by the CCITT [now ITU] as a service that provides transmission channels capable of supporting transmission rates greater than the primary data rate(64Kbps). BISDN standards are based upon the concept of an asynchronous transfer model (ATM), which will incorporate optical fiber cable as the transmission medium for data transmission. | DII MP |
| broadcast | One-way video, usually from a single transmitting site to many receiving sites. In some cases, the receiving sites can communicate to the transmitting site on an audio-only basis. | Multimedia |
| broadcast ephemeris | A set of parameters broadcast by satellite from which Earth-fixed satellite positions can be computed. In particular, the parameters for the Navy Navigation Satellites (NNS) are computed for each NNS by fitting 36- to 48-hour orbital arcs to Doppler data from four tracking stations and extrapolating this arc 12 to 24 hours beyond the last data used. The length of the arc fit and the extrapolation period depend on the upper atmospheric air density. The computed parameters are injected into the satellite memory and are transmitted along with time on each even minute. See also Navy Navigation Satellite System. | HDBK-850 |
| broken base | A base line for triangulation consisting of two or more lines that form a continuous traverse and have approximately the same general direction. | HDBK-850 |
| broken grade | (tape) The change in grade when the middle point of a tape is not on grade with its ends. If the middle support for the tape is not on the same grade as the end supports, the fact is noted with a reference "broken grade at-," naming the particular tape length which contains the broken grade. | HDBK-850 |
| broken tape measurement | (surveying) The short distances measured and accumulated to total a full tape length when a standard 100-foot tape cannot be held horizontally without plumbing from above shoulder level. Also called break tape; breaking tape. | HDBK-850 |
| broken telescope transit | A precise astronomic transit in which the light entering the objective lens is reflected at right angles by a prism placed within the telescope, the reflected light ray passing to the eyepiece, which is in the horizontal axis of the telescope. | HDBK-850 |
| broker | An intermediary that coordinates and manages the requests between clients and servers. Brokers are generally discussed in the context of CORBA (Common Object Request Broker Architecture) or other object-oriented approaches, but the usage need not be so restrictive. An example of a broker operation is to connect a client requesting some service to an available server located at some arbitrary location on the LAN. | DII COE IRTS |
| broker | A kind of intermediary service whose responsibility is only to bring other services together (typically a service requester and a service provider) and has no responsibility for satisfactory completion of the "contract" established between the requester and provider. | OpenGIS Guide |
| Brown gravity apparatus | An apparatus for measuring the acceleration of gravity which utilizes the Mendenhall pendulum, but has a clamping device for holding the pendulum in the receiver when being transported from station to station, and which utilizes an electrical pickup and amplifying device for recording the oscillations (pendulum) on the chronograph sheet. | HDBK-850 |
| browsing | The act of searching through automated information system storage to locate or acquire information without necessarily knowing of the existence or the format of the information being sought. | FED STD 1037C |
| Brunton compass | An instrument combining the features of both the sighting compass and the clinometer that can be used in the hand or upon a Jacob's staff or light tripod for reading horizontal and vertical angles, for leveling, and for reading the magnetic bearing of a line. Also called Brunton pocket transit. | HDBK-850 |
| Brunton pocket transit | See Brunton compass. | HDBK-850 |
| bubble axis | See spirit level axis. | HDBK-850 |
| bubble level | See spirit level. | HDBK-850 |
| bubble sextant | A sextant in which the bubble of a spirit level serves as the horizon. | HDBK-850 |
| bucking in | The act of aligning a theodolite to a collimator or autocollimating theodolite serving as collimator to make their lines of sight parallel and on the same plane. | HDBK-850 |
| buffer | 1. A routine or storage used to compensate for a difference in rate of flow of data, or time of occurrence of events, when transferring data from one device to another. 2. An isolating circuit used to prevent a driven circuit from influencing the driving circuit. 3. To allocate and schedule the use of buffers. [Joint Pub 6-02.1] | DISA CFS |
| bug | An error in a computer program or in a piece of electronic equipment that causes it to function improperly. | HDBK-850 |
| Bullard method of isostatic reduction | See Hayford-Bullard (or Bullard) method of isostatic reduction. | HDBK-850 |
| bull's-eye level | See circular level. | HDBK-850 |
| Bureau of Intelligence and Research (INR) | The INR, drawing on all-source intelligence, provides value-added independent analysis of events to Department of State policymakers; ensures that intelligence activities support foreign policy and national security purposes; and coordinates issues involving intelligence, security, and counterintelligence. INR's primary mission is to harness intelligence to serve U.S. diplomacy. The INR is located in Washington, DC. | STATE Web Site |
| burn | (lithography) The process of exposing a pressplate. | HDBK-850 |
| byte (B) | A sequence of adjacent bits (usually 8) considered as a unit. Note: In pre-1970 literature, "byte" referred to a variable-length bit string. Since that time the usage has changed so that now it almost always refers to an 8-bit string. This usage predominates in computer and data transmission literature; when so used, the term is synonymous with "octet". | FED STD 1037C |
| Bz curve | (photogrammetry) A graphical representation of the vertical errors in a stereotriangulated strip. In a Bz curve, the x-coordinates of the vertical control points, referred to the initial nadir point as origin, are plotted as abscissas, and the differences between the known elevations of the control points and their elevations as read in the stereotriangulated strip are plotted as ordinates; a smooth curve drawn through the plotted points is the Bz curve. The elevation read on any pass point in the strip is adjusted by the amount of the ordinate of the Bz curve for an abscissa corresponding to the x-coordinate of the point. | HDBK-850 |
| Bz curve method | A method utilizing characteristics of the Bz curve for finding the displacement of true photo plumb points from indicated projector plumb points in multiplex strip orientation. The method also provides a means of strip leveling using only the barometric altimeter readings of the aircraft flying height. | HDBK-850 |
Last Updated by Mark Owens 17 February 1999.