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Term Definition/Description Source
Pacific Air Forces (PACAF) Interim National Exploitation System (PINES) Self-contained receive, processing, storage and retrieval, exploitation, reporting, and dissemination unit with associated communications management and data base support. USIS 95
packet switching The process of routing and transferring data by means of addressed packets so that a channel is occupied during the transmission of the packet only, and upon completion of the transmission the channel is made available for the transfer of other traffic. FED STD 1037C
packet-switching network A switched network that transmits data in the form of packets. FED STD 1037C
packet-switching node In a packet-switching network, a node that contains data switches and equipment for controlling, formatting, transmitting, routing, and receiving data packets. FED STD 1037C
panchromatic (photography) Sensitive to light of all colors, as a film or plate emulsion. HDBK-850
pancratic system A variable power optical system. Also called zoom system. HDBK-850
panel 1. (cartography) See panel base. 2. (photogrammetry) An element of a target used for control station identification on aerial photography. Panels are made of cloth, plastics, plywood, or Masonite, and are positioned in a symmetrical pattern centered on the station. See also target. HDBK-850
panel base (cartography) The completed assembly of pieces of film positives onto a grid or projection which is used as a base for compilation. Also called film mosaic; panel. HDBK-850
paneling 1. (cartography) Cutting a film positive of a map, in which some distortion is involved, into several pieces and cementing them in place, on a projection constructed on a stable-base medium, in such a way that the error is distributed in small amounts throughout the area rather than being localized. 2. (surveying) The placement of panels on a control station to facilitate station identification on aerial photography. HDBK-850
panoramic camera A camera which takes a partial or complete panorama of the terrain. Some designs utilize a lens which revolves about an axis perpendicular to the optical axis; in other designs, the camera itself is revolved by clockwork to obtain a panoramic field of view. See also frame camera. HDBK-850
panoramic distortion The displacement of ground points from their expected perspective positions, caused by the cylindrical shape of the negative film surface and the scanning action of the lens in a panoramic camera system. HDBK-850
panoramic photograph Photography obtained from a panoramic camera. HDBK-850
pantograph An instrument for copying maps, drawings, or other graphics at a predetermined scale. Pantographs capable of adjustment for several scales are known as fixed ratio pantographs. See also two-dimensional pantograph. HDBK-850
paper-strip method (rectification) A graphical method of making a point-by-point rectification based on the invariance of the cross ratio. A modification of this technique permits map detail to be revised from an oblique aerial photograph based on the projectivity of straight lines. HDBK-850
parallactic aberration See differential aberration. HDBK-850
parallactic angle 1. (astronomy) The angle between a body's hour circle and its vertical circle. Also called position angle. 2. (photogrammetry) Also called angular parallax. See angle of convergence. HDBK-850
parallactic error An error caused by personal or instrument parallax. HDBK-850
parallactic grid (photogrammetry) A uniform pattern of rectangular lines drawn or engraved on some transparent material, usually glass, and placed either over the photographs of a stereoscopic pair or in the optical system of a stereoscope, in order to provide a continuous floating mark system. HDBK-850
parallactic inequality A secondary effect in solar perturbations in the Moon's longitude due to the ellipticity of the Earth's orbit. HDBK-850
parallax 1. (JCS) In photography, the apparent displacement of the position of an object in relation to a reference point due to a change in the point of observation. 2. The apparent displacement between objects on the Earth's surface due to their difference in elevation. Also called angular parallax; want of correspondence. See also absolute stereoscopic parallax; age of parallax inequality; annual parallax; equatorial horizontal parallax; false parallax; geocentric parallax; horizontal parallax; instrument parallax; lunar parallax; residual parallax; solar parallax; y-parallax. HDBK-850
parallax age See age of parallax inequality. HDBK-850
parallax bar See stereometer. HDBK-850
parallax difference The difference in the absolute stereoscopic parallaxes of two points imaged on a pair of photographs. Customarily used in determination of the difference in elevation of objects. HDBK-850
parallax in altitude Geocentric parallax at any altitude. The expression is used to distinguish the parallax at the given altitude from the horizontal parallax when the body is in the horizon. HDBK-850
parallax inequality The variation in the range of tide or in the speed of tidal currents because of the continual change in the distance of the Moon from the Earth. The range of tide and speed of tidal currents tend to increase as the Moon approaches perigee and to decrease as it approaches apogee. HDBK-850
parallel A circle on the surface of the Earth, parallel to the plane of the Equator and connecting all points of equal latitude, or a circle parallel to the primary great circle of a sphere or spheroid; also, a closed curve approximating such a circle. Also called inverse parallel. See also astronomic parallel; ecliptic parallel; fictitious parallel; geodetic parallel; geographic parallel; grid parallel; ground parallel; isometric parallel; oblique parallel; photograph parallel: principal parallel; standard parallel; transverse parallel. HDBK-850
parallel of altitude A circle of the celestial sphere parallel to the horizon connecting all points of equal altitude. Also called almucantar; altitude circle; circle of equal altitude. HDBK-850
parallel of declination A circle of the celestial sphere parallel to the celestial equator. Also called celestial parallel; circle of equal declination. HDBK-850
parallel of latitude See circle of longitude. HDBK-850
parallel plate An optical disk with optically flat, parallel surfaces; used especially in optical micrometers. Also called plane plate. See also optical flat. HDBK-850
parallel sphere The celestial sphere as it appears to an observer at the pole, where celestial bodies appear to move parallel to the horizon. HDBK-850
parameter In general, any quantity of a problem that is not an independent variable. More specifically the term is often used to distinguish from dependent variables quantities which may be assigned arbitrary values for purposes of the problem at hand. HDBK-850
parameter passing mode Describes the direction of information flow for an operation parameter. The parameter passing modes are IN, OUT, and INOUT. CORBA 2.2
parameterize The act or process of describing a geometric situation with a mathematical model containing adjustable constants. HDBK-850
parametric equations A set of equations in which the independent variables or coordinates are each expressed in terms of a parameter. HDBK-850
parametric latitude The angle at the center of a sphere which is tangent to the ellipsoid along the geodetic equator, between the plane of the equator and the radius to the point intersected on the sphere by a straight line perpendicular to the plane of the Equator and passing through the point on the ellipsoid whose parametric latitude is defined. Parametric latitude is an auxiliary latitude used in problems of geodesy and cartography. HDBK-850
paraxial ray A ray whose path lies very near the axis of a lens and which intersects the lens surface at a point very close to its vertex and at nearly normal incidence. HDBK-850
partial tide See constituent. HDBK-850
participating activity The activity responsible for resolving and consolidating coordination comments on standardization program plans within its Military Department or Defense Agency, and submitting those comments to the LSA [Lead Standardization Activity]. [DOD 4120.3-M] DISA CFS
part-of relationship A relationship between two entities or two features in which one is a component of the other. ISO/TC 211
pass 1. A single circuit of the Earth by a satellite. See also orbit. 2. The period of time a satellite is within telemetry range of a data acquisition station. 3. (mensuration) One complete set of pointings or measurements on a specific plate, reseau, or other media containing photographic imagery. HDBK-850
pass The term used to refer to a specific revolution in the course of an imaging day, beginning with pass one and continuing through the last revolution of the same day. USIS 95
pass point A point whose horizontal and/or vertical position is determined from photographs by photogrammetric methods and which is intended for use in the absolute orientation of a model. Also called photogrammetric point. See also annex point; supplemental elevation; supplemental position. HDBK-850
pass verdict A test verdict given when the observed test outcome gives evidence of conformance to the conformance requirement on which the test purpose is focused and is valid with respect to the relevant standard(s) and with respect to the specified statement. ISO/TC 211
passive remote sensing Remote sensing of energy naturally reflected or radiated from the terrain. USIS 95
passive satellite A satellite which contains no power sources to augment output power; a satellite which is a passive reflector. See also active satellite. HDBK-850
patch (digital) A small area of information spliced into a data base or software in order to update, complete, or densify the data content. HDBK-850
path The projection of the orbital plane of the satell'te on the Earth's surface; the locus of the satellite subpoint. HDBK-850
Pathfinder Pathfinder is a process that provides a critical link between commercial and government developers of technologies and the analyst users. With its beginning in Project Beacon (1995) and continuous improvement through Pathfinder 96, 97, and 98, key technologies continue to be identified, evaluated, and recommended for insertion to qualitatively and quantitatively improve the analysts' processes. The ultimate beneficiaries are the many different NIMA customers. NIMA Web Site
PC-1000 camera A trade name for a geodetic stellar camera having a focal length of 1,000 mm. HDBK-850
Peaucellier inversor A class of inversor providing a mechanical solution for the linear and angular elements of rectification. Also called scissors inversor. HDBK-850
Peaucellier-Carpentier inversor A modified Carpentier inversor coupled to the linkage system of a Peaucellier inversor to provide a mechanical means of solving the linear and angular elements of rectification. HDBK-850
peel (negative engraving) A technique of removing the opaque stratum from its supporting base. Peeling between etched outline images produces a negative; peeling outside of the etched outline images produces a positive. See also mask, definition 2. HDBK-850
peepsight alidade A type of alidade consisting of a peep sight mounted on a straightedge. HDBK-850
peepsight compass The sights of a compass formed by standards with slits for a sighting medium rather than a telescope. HDBK-850
peer protocol The protocol governing communications between program entities that have the same function in the same layer in each of two OSI networks. TAFIM 3.0
peg adjustment A method of adjusting a leveling instrument of the dumpy level type, to make the line of collimation parallel with the axis of the spirit level, and employing two stable marks (pegs) the length of one instrument sight apart. Also called 11/10 peg adjustment. HDBK-850
peg test A method of testing the collimation adjustment of a leveling instrument. HDBK-850
Pemberton leveling rod A speaking rod marked with alternate rows of circular and diamond-shaped dots, running diagonally across the rod. Read to hundredths of a foot. HDBK-850
pendulum 1. In general, a body so suspended as to swing freely to and fro under the influence of gravity and momentum. 2. A vertical bar so supported from below by a stiff spring as to vibrate to and fro under the combined action of gravity and the restoring force of the spring. See also compound pendulum; dummy pendulum; free-swinging pendulum; idle pendulum; Invar pendulum; invariable pendulum; Mendenhall pendulum; quartz pendulum; receiver; relative pendulum; reversible pendulum; simple pendulum; working pendulum. HDBK-850
pendulum alidade A telescopic alidade in which a pendulum device replaces the conventional bubble for establishing a horizontal reference line from which vertical angles may be measured. HDBK-850
pendulum astrolabe An astronomic instrument using a constant altitude for position determination. Its distinctive feature is a mirror suspended on top of a pendulum to form the artificial horizon. HDBK-850
pendulum level A leveling instrument in which the line of sight is automatically maintained horizontal by means of a built-in pendulum device. Also called automatic level. HDBK-850
percent of slope See gradient. HDBK-850
performance A measure of a computer system or subsystem to perform its functions; for example, response time, throughput, number of transactions per second. The efficiency of a system in accomplishing pieces of work is an attribute of performance. IEEE P1003.0
Performance Goal A Performance Goal is defined as a target level of performance and is expressed as a tangible, measurable objective, by which actual achievement or performance can be measured or compared. A performance goal is expressed as a quantitative rate, value or standard. [DISA/D5] DISA CFS
performance requirement A requirement that specifies a performance characteristic that a system or system component must possess; for example, speed, accuracy, frequency. IEEE P1003.0
periapsis See pericenter. HDBK-850
periastron That point of the orbit of one member of a double star system at which the stars are nearest together. Opposite of apastron. HDBK-850
pericenter In an elliptical orbit the point in the orbit which is the nearest distance from the focus where the attracting mass is located. The pericenter is at one end of the major axis of the orbital ellipse. Opposite of apoapsis; apocenter; apofocus. Also called periapsis; perifocus. HDBK-850
pericynthion See perilune. HDBK-850
perifocus See pericenter. HDBK-850
perigee The point at which a satellite orbit is the least distance from the center of the gravitational field of the earth. Opposite of apogee. HDBK-850
perigee-to-perigee period See anomalistic period. HDBK-850
perihelion The point in the elliptical orbit of a planet which is the nearest to the Sun, when the Sun is the center of attraction. Opposite of aphelion. HDBK-850
perilune The point of closest approach of an orbiting body to the Moon. Opposite of aplune; apocynthion. Also called pericynthion. HDBK-850
period 1. The interval needed to complete a cycle. 2. The interval between passages at a fixed point of a given phase of a simple harmonic wave; the reciprocal of frequency. See also anomalistic period; nodical period; orbital period; sidereal period; synodic period. HDBK-850
period Duration of time specified by its beginning and end points. [ISO 8601:1988] ISO/TC 211
period of satellite See orbital period. HDBK-850
periodic errors In a complete set of observations there corresponds to every individual error another error which is necessarily more or less equal and opposite. In a limited series the cancellation may not be quite exact, but the error of the mean of n observations may be expected to be 1/n of that of a single measure, or less. HDBK-850
periodic intelligence summary A report of the intelligence situation in a tactical operation, normally produced at Corps level or its equivalent, and higher, usually at intervals of 24 hours, or as directed by the commander. USIS 95
periodic perturbations Perturbations to the orbit of a planet or satellite which change direction in regular or periodic fashion in time, such that the average effect over a long period of time is zero. HDBK-850
periodic terms In the mathematical expression of an orbit, terms which vary with time in both magnitude and direction. HDBK-850
periodic time Tthe time of one cycle. [ISO 31-2:1992] ISO/TC 211
periodicity The frequency with which a target is due to be collected. USIS 95
permanent bench mark (PBM) A bench mark of as nearly permanent character as it is practicable to establish. Usually designated simply as a bench mark or BM. A permanent bench mark is intended to maintain its elevation with reference to an adopted datum without change over a long period of time. Also called monumented bench mark. HDBK-850
permission A prescription that a particular behavior is allowed to occur. A permission is equivalent to there being no obligation for the behavior not to occur. RM-ODP
perpendicular A perpendicular line, plane, etc. A distinction is sometimes made between perpendicular and normal, the former applying to a line at right angles to a straight line or plane, and the latter referring to a line at right angles to a curve or curved surface. HDBK-850
perpendicular equation (traverse) A condition equation to reduce to zero the algebraic sum of the projections of the separate lines of a traverse upon perpendiculars to a fixed line with which the traverse forms a closed figure. HDBK-850
persistence The property that an object continues to exist across changes of contractual context of an epoch. RM-ODP
Persistence Transparency A distribution transparency which masks, from an object, the deactivation and reactivation of other objects (or itself). Deactivation and reactivation are often used to maintain the persistence of an object when the system is unable to provide it with processing, storage, and communication functions continuously. RM-ODP
persistent object An object that can survive the process or thread that created it. A persistent object exists until it is explicitly deleted. CORBA 2.2
personal equation The time interval between the sensory perception of a phenomenon and the motor reaction thereto. A personal equation may be either positive or negative, as an observer may anticipate the occurrence of an event, or wait until he actually sees it occur before making a record. This is a systematic error, treated as the constant type. HDBK-850
personal error An error caused 'y an individual's personal habits, his inability to perceive or measure dimensional values exactly, or by his tendency to react mentally and physically in a uniform manner under similar conditions. It may be a systematic error, if it occurs regularly or a blunder if it occurs once. A certain amount of minor personal error can be included with random errors. HDBK-850
personal parallax See instrument parallax, definition 2. HDBK-850
perspective The appearance to the eye of objects in respect to their relative distance and position. HDBK-850
perspective axis See axis of homology. HDBK-850
perspective center The point of origin or termination of bundles of perspective rays. The two such points usually associated with a survey photograph are the interior perspective center and the exterior perspective center. In a perfect lens-camera system, perspective rays from the interior perspective center to the photographic images enclose the same angles as do the corresponding rays from the exterior perspective center to the objects photographed. In a lens having distortion, this is true only for a particular zone of the photograph. In a perfectly adjusted lens-camera system, the exterior and interior perspective centers correspond, respectively, to the front and rear nodal points of the camera lens. Also called center of projection. HDBK-850
perspective chart A chart on a perspective projection. HDBK-850
perspective drawing A line drawing showing several different views of a scene, a geometrical projection of an object on a plane perpendicular to the horizon, a technical presentation on a plane or curved surface of the spatial relationships of objects as they appear to the eye and give the impression of distance. USIS 95
perspective grid (JCS) A network of lines, drawn or superimposed on a photograph, to represent the perspective of a systematic network of lines on the ground or datum plane. Also called Canadian grid. See also grid method. HDBK-850
Perspective Image Generation & Exploitation A DIA image perspective transformation system. USIS 95
perspective map projection A map projection produced by straight lines radiating from a selected point and passing through poi'ts on the earth's surface to the projection surface. Also called geometric map projection. HDBK-850
perspective plane Any plane containing the perspective center. The intersection of a perspective plane and the ground will always appear as a straight line on an aerial photograph. HDBK-850
perspective projection The projection of points by straight lines drawn through them from some given point to an intersection with the plane of projection. Unless otherwise indicated, the point of projection is understood to be at a finite distance from the plane of projection. HDBK-850
perspective ray A line joining a perspective center and a point object. See also image ray. HDBK-850
perspective spatial model Optical reconstruction of an area of terrain showing depth by viewing a pair of aerial photographs through a stereoscope. HDBK-850
perspective view A three-dimensional representation generated with a reference to a specific viewer location on or above the surface portrayed. HDBK-850
perspectivity The correspondence between the points, lines, or planes of two geometric configurations in perspective. Usually referred to as linear perspectivity because the true perspective center must be recoverable before angular perspectivity can be included. HDBK-850
perturbation In celestial mechanics, differences of the actual orbit from a central force orbit, arising from some external force such as a third body attracting the other two; a resisting medium (atmosphere); failure of the parent body to act as a point mass, and so forth. See also gravitational perturbations; long period perturbations; lunisolar perturbations; nongravitational perturbations; periodic perturbations; secular perturbations; short period perturbations; terrestrial perturbations. HDBK-850
perturbed orbit The orbit of a satellite differing from its normal orbit due to various disturbing effects such as nonsymmetrical gravitational effects, atmospheric drag, radiation pressure, and so forth. See also perturbation. HDBK-850
perturbing factors (forces) In celestial mechanics, any force that acts on the orbiting body to change its orbit from a central force orbit. HDBK-850
phase 1. (general) Of a periodic quantity, for a particular value of the independent variable, the fractional part of a period through which the independent variable has advanced, measured from an arbitrary reference. 2. (surveying) The apparent displacement of an object or signal caused by one side being more strongly illuminated than the other. The resultant error in pointing is similar to the error caused by observing an eccentric signal. 3. (astronomy) A stage in a cycle of recurring aspects, caused by a systematic variation of the illumination of an object. The Moon passes through its phases, new Moon to full Moon and back to new Moon, as its position relative to the Sun and Earth changes. HDBK-850
phase age See age of phase inequality. HDBK-850
phase angle 1. The phase difference of two periodically recurring phenomena of the same frequency, expressed in angular measure. 2. The angle at a celestial body between the Sun and Earth. HDBK-850
phase inequality Variations in the tide or tidal currents associated with changes in the phase of the Moon. At new and full Moon (springs) the tide-producing forces of the Sun and Moon act in conjunction, resulting in greater than average tide and tidal currents. At first and last quarters of the Moon (neaps) the tide-producing forces oppose each other, resulting in smaller than average tide and tidal currents. HDBK-850
phenomenon A fact, occurrence or circumstance. EXAMPLE - Route 10; George Washington National Forest; Chesterfield County. ISO/TC 211
Philadelphia leveling rod A two-piece target rod, with graduation marks so styled that it may also be used as a speaking rod. For heights greater than 7 feet the target is clamped at 7 feet, and raised by extending the rod. As a target rod, it is read by vernier to thousandths of a foot; as a speaking rod, to half-hundredths of a foot. HDBK-850
photo altitude Height of an aircraft above the mean elevation of the terrain to be photographed. HDBK-850
photo index 1. An index map made by assembling the individual aerial photographs into their proper relative positions and copying the assembly photographically at a reduced scale. Also called index to photography; photo plot; plot map. 2. See sortie plot. HDBK-850
photo plot See photo index, definition 1. HDBK-850
photo pyramid A component of an analytical method of precise determination of photographic tilt which represents a specific spatial configuration formed by three control points of known position on the photograph (forming a triangle) and the exposure station. When used with the ground pyramid, it permits the exact position of the exposure station to be determined and, by analytical techniques, the exact tilt of the photograph. See also ground pyramid. HDBK-850
photo revision The process of making changes on a map based upon information obtained from a study of aerial photographs. HDBK-850
photo scale See scale, definition 1. HDBK-850
photoalidade A photogrammetric instrument having a telescopic alidade, a plateholder, and a hinged ruling arm mounted on a tripod frame. It is used for plotting lines of direction and measuring vertical angles to selected features appearing on oblique and terrestrial photographs. HDBK-850
photoangulator See angulator. HDBK-850
photobase The distance between the principal points of two adjacent prints of a series of vertical aerial photographs. It is usually measured on one print after transferring the principal point of the other print. See also base line, definition 2. HDBK-850
photocompose To mechanically impose one or more images by step-and-repeat exposures in predetermined positions on a press plate or negative by means of a photocomposing machine. HDBK-850
photocontour map Essentially, a topographic map upon which the planimetric detail is depicted photographically in its correct position. It is usually prepared from convergent photography although conventional vertical photography can be used. HDBK-850
photocontour process A process developed to combine, in a photocontour map, that information normally portrayed on a topographic drawing and an aerial photograph. The system usually is composed of three elements: (1) a conventional stereoplotter for contouring; (2) a rectifier for tilt rectification of the aerial photographs; and (3) a zone printer to eliminate relief displacement. It is designed to utilize convergent photographs although normal vertical photographs can be utilized as well. HDBK-850
photocontrol base See control base. HDBK-850
photocontrol diagram Any selected base map or photo index on which proposed ground control networks, to include proposed positions for pass points, are delineated. See also photocontrol index map. HDBK-850
photocontrol index map Any selected base map or photo index on which ground control and photo identified ground points are depicted and identified. See also photocontrol diagram. HDBK-850
photocontrol point See picture control point. HDBK-850
photogoniometer An instrument for measuring angles from the true perspective center to points on a photograph. HDBK-850
photogrammetric camera A general term applicable to any camera used in any of the several branches of photogrammetry. HDBK-850
photogrammetric compilation See compilation, definition 2. HDBK-850
photogrammetric control (JCS) Control established by photogrammetric methods as distinguished from control established by ground methods. Also called minor control; multiplex control. HDBK-850
photogrammetric control point A horizontal control point which has been established by photogrammetric triangulation. HDBK-850
photogrammetric map A topographic map produced from aerial photographs and geodetic control data by means of photogrammetric instruments. Also called stereometric map; stereotopographic map. HDBK-850
photogrammetric point See pass point. HDBK-850
photogrammetric pyramid An analytical method for the precise determination of photographic tilt, consisting of a ground pyramid and a photo pyramid, which represent a spatial configuration formed by three control points of known position on the photograph (forming a triangle) and the exposure station. See also ground pyramid; photo pyramid. HDBK-850
photogrammetric rectification See rectification. HDBK-850
photogrammetric survey A survey utilizing either terrestrial or aerial photographs. HDBK-850
photogrammetric triangulation See phototriangulation. HDBK-850
photogrammetrically digitized Digitized from aerial photographs and geodetic control data by means of photogrammetric instruments, providing three-dimensional coordinates. HDBK-850
photogrammetry 1. (JCS) The science or art of obtaining reliable measurements from photographic images. 2. The preparation of charts and maps from aerial photographs using stereoscopic equipment and methods. See also aerial photogrammetry; analytical photogrammetry; stereophotogrammetry; terrestrial photogrammetry. HDBK-850
photogrammetry The science of mensuration and geometric adjustment of, an aerial photograph or satellite image. Photogrammetry requires: a mathematical model of the image formation process, computation of the internal geometry of an image, and subsequent correction of imagery based upon the ground relationship for every part of the image. Correction of imagery based on computational algorithms and measurement of geometrical position in an image. OGC RFI
photogrammetry Use of aerial photographs to produce planimetric and topographic m'ps of the earth's surface and of features of the built environment. Effective photogrammetry makes use of ground control by which aerial photographs are carefully compared and registered to the locations and characteristics of features identified in ground-level surveys. OpenGIS Guide
photograph A general term for a positive or negative picture made with a camera on sensitized material, or prints from such a camera original. See also aerial photograph; annotated photograph; equivalent vertical photograph; homologous photographs; horizon photograph; horizontal photograph; molded aerial photograph; multiple-lens photograph; oblique air photograph; orthophotograph; panoramic photograph; pinpoint photograph; terrestrial photograph; vertical photograph; wing photo-graph. HDBK-850
photograph Imagery of a scene formed by the reaction of electromagnetic energy on a photosensitive surface. USIS 95
photograph center The center of a photograph as indicated by the images of the fiducial mark(s) of the camera. In a perfectly adjusted camera, the photograph center and the principal point are identical. HDBK-850
photograph coordinates A system of coordinates, either rectangular or polar, describing the position of a point on a photograph. HDBK-850
photograph meridian The image on a photograph of any horizontal line in the object space which is parallel to the principal plane. Since all such lines meet at infinity, the image of the meeting point is at the intersection of the principal line and the horizon trace and all photograph meridians pass through that point. HDBK-850
photograph nadir The point at which a vertical line through the perspective center of the camera lens pierces the plane of the photograph. Also called nadir point; photographic plumb point; plumb point. HDBK-850
photograph parallel The image on a photograph of any horizontal line in the object space which is perpendicular to the principal plane. All photograph parallels are perpendicular to the principal line. HDBK-850
photograph perpendicular The perpendicular from the interior perspective center to the plane of the photograph. HDBK-850
photograph plane The plane in the camera in which the plate or film is held. It is not exactly the primary focal plane of the lens, but is a plane placed so as to secure the best balance of sharp focus on all parts of the plate or film. Also called image plane. HDBK-850
photograph plumb point See photograph nadir. HDBK-850
photographic coverage (JCS) The extent to which an area is covered by photography from one mission or a series of missions or in a period of time. Coverage in this sense conveys the ideal of availability of photography and is not a synonym for the word photography. HDBK-850
photographic datum The effective datum for each photograph. It is a horizontal plane at the average elevation of the terrain, on which distances measured will be at the average scale of the photograph. HDBK-850
photographic exposure The time of exposure multiplied by irradiance or illuminance. HDBK-850
photographic interpretation The examination of photographic images for the purpose of identifying objects and deducing their significance. Also called photointerpretation. See also imagery interpretation. HDBK-850
photographic reading (JCS) The simple recognition of natural or man-made features from photographs not involving imagery interpretation techniques. HDBK-850
photographic reduction The production of a negative, diapositive, or print at a scale smaller than the original. HDBK-850
photographic scale (JCS) The ratio of a distance measured on a photograph or mosaic to the corresponding distance on the ground, classified as follows: very large-scale-1:4,999 and larger; large-scale - 1:5,000 to 1:9,999; medium-scale - 1:10,000 to 1:24,999; small-scale - 1:25,000 to 1:49,999; very small-scale - 1:50,000 and smaller. See also scale. HDBK-850
photographic survey A survey accomplished from either aerial photographs or terrestrial photographs, or from a combination of both. HDBK-850
photographic zenith tube (PZT) The most precise instrument for meridian observations. No corrections are required for level, azimuth, collimation, or flexure. Each observation gives a measure of both the time and the latitude. HDBK-850
photography The art or process of producing images on sensitized material through the action of light. The term photography is sometimes incorrectly used in place of the term photographs. See also analytical photography; composite air photography; continuous strip photography; control point photography; convergent photography; cross-flight photography; direct photography; fan camera photography; horizontally controlled photography; indirect photography; inertial reference photography; lorop photography; mapping photography; metric photography; multiband photography; positional camera photography; process photography; radar photography; radarscope photography; reconnaissance photography; shoran controlled photography; split vertical photography; supplemental photography; terrain profile photography; tricamera photography. HDBK-850
photoidentification (surveying) The detection, identification, and marking of ground survey stations on aerial photographs. Positive identification and location is required if survey data are to be used to control photogrammetric compilation. Also called control-station identification. HDBK-850
photointerpretation See photographic interpretation. HDBK-850
photointerpretation key Reference materials designed to facilitate rapid and accurate identification and the determination of the significance of objects or conditions from an analysis of their photo images. HDBK-850
photointerpretometer A device, used in conjunction with a pocket stereoscope, for making vertical and horizontal measurements. HDBK-850
photolithography A lithographic process in which photographic products are used to produce an image on the printing surface. See also lithography; offset lithography. HDBK-850
photomap (JCS) A reproduction of a photograph or photomosaic upon which the grid lines, marginal data, contours, place names, boundaries, and other data may be added. HDBK-850
photomap backup A photomap printed on the back of a line map of the same area and at the same scale. HDBK-850
photomapping The process of making maps or charts from various types of photographs, with reference to other source maps, charts, or surveys. HDBK-850
photomechanical Pertaining to or designating any reproduction process by a combination of photographic and mechanical operations. HDBK-850
photorevised map A topographic or planimetric map which has been revised by photoplanimetric methods. HDBK-850
photosphere The intensely bright portion of the Sun visible to the unaided eye. HDBK-850
phototheodolite A ground surveying instrument combining a survey camera and a transit; used for measuring the angular orientation of the camera at the moment of exposure. Also called camera transit. HDBK-850
phototopography The science of surveying in which the detail is plotted entirely from photographs taken at suitable ground stations. See also terrestrial photogrammetry. HDBK-850
phototriangulation The process for the extension of horizontal and/or vertical control whereby the measurements of angles and/or distances on overlapping photographs are related into a spatial solution using the perspective principles of the photographs, Generally, this process involves using aerial photographs and is called aerotriangulation, aerial triangulation, or photogrammetric triangulation. See also analytical nadir-point triangulation; analytical phototriangulation; analytical radial triangulation; Arundel method; bridging; cantilever extension; direct radial triangulation; extension of control; graphical radial triangulation; hand-templet triangulation; isocenter triangulation; mechanical templet triangulation; nadir-point triangulation; radial triangulation; slotted-templet triangulation; spider-templet triangulation; stereotemplet triangulation; stereotriangulation; strip radial triangulation; templet method. HDBK-850
phototrig traverse A vertical-angle traverse employing phototrig methods; a procedure for determining elevations trigonometrically, wherein horizontal distances are determined photo- grammetrically and vertical angles are either measured instrumentally in the field, or are obtained from measurements on terrestrial photographs. HDBK-850
phototypesetter A type setting unit comprising two separate and independent units, the keyboard unit and the photographic unit. Composition is accomplished at the keyboard unit, essentially an electric typewriter, which produces a typewritten proof copy and a perforated tape. The tape is then fed at any convenient time thereafter to the photographic unit which produces a right-reading film positive suitable for stickup work. HDBK-850
physical characteristic (target) The visible material aspects of a target or installation, including, but not limited to, dimensions, structural materials, predominant height, configuration, and orientation of its various components such as buildings, structures, runways, and associated facilities and services. HDBK-850
physical data model (PDM) A data model that represents the implementation of the data contained in a data structure. [IEEE 610.5] Compare to conceptual data model (CDM) and logical data model (LDM). IEEE 610-1990
physical geodesy See gravimetric geodesy. HDBK-850
physical layer The first layer of the OSI Reference Model. It governs hardware connectors and byte-stream encoding for transmission. It is the only layer that involves a physical transfer of information between network nodes. TAFIM 3.0
physical view The physical viewpoint represents the overall structu'e of the system's implementation. It shows the system in terms of physically identifiable components and their connectors. IEEE 1471
physiographic pictorial map A map with relief depicted by the systematic application of a standardized set of conventional pictorial symbols, based on the simplified appearance of the physical features they represent, as viewed obliquely from the air at an angle of about 45. HDBK-850
piano-wire tape Piano wire used instead of a metallic ribbon tape when it is advisable to control hydrography by precise traverse rather than by a weak extension of triangulation, HDBK-850
pictochrome process The process employed to produce pictomaps. Consists of three tonal separations photographically extracted from a photomosaic, blockout masks, drafted symbols, and names data. HDBK-850
pictogram A map of distributions, especially commodities in which small pictorial representative symbols (e.g., sacks, bricks, barrels) are located over the area of production. HDBK-850
pictoline process A photographic masking process utilizing a rotating vacuum frame to produce an edge-enhanced line image from a continuous tone image. HDBK-850
pictomap (JCS) A topographic map in which the photographic imagery of a standard mosaic has been converted into interpretable colors and symbols by means of a pictomap process. See also pictochrome process. HDBK-850
pictorial symbolization (JCS) The use of symbols which convey the visual character of the features they represent. HDBK-850
pictotone process A photo- lithographic method from which film for reproduction and transfer to printing plates is derived for the printing of monochrome photomaps and pictomaps. The process provides a random granular-like effect which visibly sharpens the definition of features and separation of tones, and, in many instances, is superior to halftone printing. HDBK-850
picture control points Supplementary horizontal and vertical control points that are required for the immediate control of mapping operations in a given area. These points are established by field survey parties in specific locations and are precisely identified on the aerial photographs for the project. Also called photocontrol point; picture point. HDBK-850
picture element (pixel) See pixel. [IEEE 610.4] IEEE 610-1990
picture plane A plane upon which can be projected a system of lines or rays from an object to form an image or picture. In perspective drawing, the system of rays is understood to converge to a single point. In photogrammetry, the photograph is the picture plane. HDBK-850
picture point See control point; picture control points. HDBK-850
pilot See sailing directions. HDBK-850
pilot chart Special charts, covering the oceans of the world for each month of the year, issued on one sheet for 3 months at a time on a quarterly basis. They show meteorologic, oceanographic, and hydrographic data for use in conjunction with conventional charts. Timely articles of professional interest to the seafarer are published on the backs. HDBK-850
pilot sheet A sample of a new series, made as a trial in anticipation of a map series, to disclose the problems which occur in the various stages of compilation, drafting, and reproduction. It is later used as a guide in developing the series. Also called prototype. See also experimental map. HDBK-850
pilot's trace (JCS) A rough overlay to a map made by the pilot of a photographic reconnaissance aircraft during or immediately after a sortie. It shows the location, direction, number, and order of photographic runs made, together with the camera(s) used on each run. HDBK-850
pin (surveying) A metal pin used for marking taped measurements on the ground. A set consists of 11 pins. Also called chaini'g pin; surveyor's arrow; taping arrow; taping pin. See also turning point pin. HDBK-850
pinholes Tiny clear spots on negative images caused by dust, air bubbles, or undissolved chemicals. HDBK-850
pinpoint photograph (JCS) A single photograph or a stereopair of a specific object or target. HDBK-850
pinpoint target (JCS) In artillery and naval gunfire support, a target less than 50 meters in diameter. See also area target; precise installation position. HDBK-850
pitch 1. (JCS) The rotation of an aircraft or ship about its lateral axis. 2. (JCS) In air photography, the camera rotation about the transverse axis of the aircraft. 3. (photogrammetry) A rotation of the camera, or of the photograph coordinate system, about either the photograph y-axis or the exterior y-axis. In some photogrammetric instruments and in analytical applications, the symbol phi (f) may be used. Also called longitudinal tilt; tip (which is an obsolete term); y-tilt. HDBK-850
pixel (PIX [picture] Element) The smallest element on a video display screen. A screen is broken up into thousands of tiny dots, and a pixel is one or more dots that are treated as a unit. A pixel can be one dot on a monochrome screen, three dots (red, green and blue) on color screens, or clusters of these dots. Freedman 1995
pixel A picture element, smallest unit of information in a grid cell map or scanner image. Also known as PEL. HDBK-850
pixel In image processessing, the smallest element of a digital image that can be assigned a gray level. Note: This term originated as a contraction for "picture element". Syn: pel; picture element; resolution cell. [IEEE 610.4] IEEE 610-1990
pixel A 2-dimensional picture element that is the smallest nondivisible element of a digital image. ISO/TC 211
pixelization The appearance of individual pixels in an image scene, that determines the limit of image quality. USIS 95
place See position, definition 2. HDBK-850
place name See toponym. HDBK-850
plain attribute An attribute that has a domain that is defined as a simple type in the EXPRESS language. CEN/TC 287
plan position indicator (PPI) 1. (JCS) A cathode-ray tube on which radar returns are so displayed as to bear the same relationship to the transmitter as the objects giving rise to them. 2. A cathode-ray indicator in which a signal appears on a radial line. Distance is indicated radially and bearing as an angle. HDBK-850
plan range (JCS) In air photographic reconnaissance, the horizontal distance from the point below the aircraft to an object on the ground. HDBK-850
planar extent The horizontal extent of a dataset. CEN/TC 287
planar graph A representation of node, link and chain objects as though they occur upon a planar surface. NOTE - Not more than one node may exist at any given point on the surface. Links or chains may only intersect at nodes. See also Level 2 topology. ISO/TC 211
plane See astronomic meridian plane; basal plane; collimation plane; epipolar plane; focal plane; geodetic meridian plane; ground plane; hill plane; horizontal plane; meridional plane; nodal plane; orbital plane; perspective plane; photograph plane; picture plane; principal plane; tangent plane; vertical plane. HDBK-850
plane coordinates See plane rectangular coordinates. HDBK-850
plane curve See plane elliptical arc. HDBK-850
plane elliptical arc Any part of the line formed by the intersection of a plane and an ellipsoid. Also called plane curve. HDBK-850
plane parallel plate See parallel plate. HDBK-850
plane polar coordinates A system of polar coordinates in which the points all lie in one plane. In the terminology of analytical geometry, the distance from the origin to the point is the magnitude of the radius vector and the polar distance is the vectorial angle. HDBK-850
plane rectangular coordinates A system of coordinates in a horizontal plane, used to describe the positions of points with respect to an origin. Also called plane coordinates. HDBK-850
plane survey A survey in which the surface of the Earth is considered a plane. For small areas, precise results may be obtained with plane-surveying methods, but the accuracy and precision of such results will decrease as the area surveyed increases in size. HDBK-850
planet A celestial body of the solar system revolving around the Sun in a nearly circular orbit, or a similar body revolving around a star. See also asteroid; inferior planets; inner planets; major planets; navigational planets; outer planets; principal planets; superior planets; terrestrial planet. HDBK-850
planetable A field device for plotting the lines of a survey directly from observations. It consists essentially of a drawing board mounted on a tripod, with a leveling device designed as part of the board and tripod. See also alidade; Philadelphia leveling rod; stadia. HDBK-850
planetable map A map compiled by planetable methods. The term includes maps made by complete field mapping on a base projection and field contouring on a planimetric base map. HDBK-850
planetable traverse A graphical traverse accomplished by planetable methods. HDBK-850
planetary aberration The angular displacement of the geometric direction between the object and the observer at the instant of light emission, from the geometric direction at the instant of observation. HDBK-850
planetary configurations Apparent positions of the planets relative to each other and to other bodies of the solar system, as seen from the Earth. HDBK-850
planetary geometry 1. Mathematical treatment of the shape and figure of a planet. 2. Mathematical treatment of relationships between two or more planets and/or their orbits. HDBK-850
planetary precession That component of general precession caused by the effect of other planets on the equatorial protuberance of the Earth, producing an eastward motion of the equinoxes along the ecliptic. HDBK-850
planetoid See asteroid. HDBK-850
planimeter A mechanical integrator for measuring the area of a plane surface. See also polar planimeter. HDBK-850
planimetric The horizontal (x,y) locations of non-topographic features, such as rivers, lakes, buildings, roads, etc. USIS 95
planimetric map (JCS) A map representing only the horizontal position of features. Also called line map. See also topographic map. HDBK-850
planimetric-base map A map prepared from aerial photographs by photogrammetric methods, as a guide or base for contouring. HDBK-850
planimetry 1. The science of measuring plane surfaces; horizontal measurements. 2. Parts of a map which represent everything except relief; that is, works of man, and natural features such as woods and water. HDBK-850
planisphere A representation, on a plane, of the celestial sphere, especially one on a polar projection, with means provided for making certain measurements such as altitude and azimuth. Also, a map representation, on a plane, of the Earth's sphere. HDBK-850
planispheric astrolabe An astrolabe consisting of a full graduated circle with a centrally mounted alidade and accessory adjustable plates on which are engraved stereographic projections of the heavens and of the sphere for local latitudes. HDBK-850
planning and direction Establishing the command relationships between all intelligence elements within the joint force and identifying, prioritizing, and validating intelligence and intelligence system requirements. JPUB 2-0
planning chart A chart designed specifically for planning flight operations. HDBK-850
planning map Small-scale military map used for general planning purposes. HDBK-850
Planning Terrain Analysis Data Base (PTADB) A 1:250,000 scale hardcopy, geographic information system consisting of a set of selected single thematic terrain information overlays. HDBK-850
Planning, Programming, and Budgeting System (PPBS) DoD budgetary system for tactical intelligence and related activities (TIARA) funds. USIS 95
plastic block The block of bonded cellulose acetate sheets, each sheet equal in thickness to the contour interval at the scale of the relief model, from which the terrain base is cut. Also called laminate. HDBK-850
plastic relief map A topographic map printed on plastic and molded into a three-dimensional form. The plastic medium is generally formed by heat and vacuum over a terrain model to achieve the three-dimensional representation. HDBK-850
plat A diagram drawn to scale showing land boundaries and subdivisions, together with all data essential to the description and identification of the several units shown thereon, and including one or more certificates indicating due approval. A plat differs from a map in that it does not necessarily show additional cultural, drainage, and relief features. See also cadastral map. HDBK-850
plate 1. (lithography) A thin metal, plastic, or paper sheet, that carries the printing image and whose surface is treated to make only the image areas ink receptive. Also called press plate. See also color plate; combination plate. 2. (photography) A transparent medium, usually glass, coated with a photographic emulsion. See also diapositive; stellar plate. HDBK-850
plate coordinates The x- and y-coordinates of control points appearing on a photographic plate. HDBK-850
plate level A spirit level attached to the plate of a surveying instrument for leveling the graduated circle or, indirectly, making the vertical axis truly vertical. HDBK-850
plate reduction Scaling of control point images on a stellar plate. HDBK-850
platform (A&D LDM Entity: "PLATFORM") A commercial collection platform. A&D LDM
platform A system that is a physical structure that hosts systems or systems components. Note: A kind of system element in the CADM. C4ISR AF
platform The vehicle that holds a sensor. It is usually a satellite, but may be a plane or a helicopter. Sensors can be mounted on tripods for certain uses, such as examining electromagnetic radiation from various types of vegetation. HDBK-850
platform Another term for computer hardware, including microcomputers, workstations, and mainframe computers, or for underlying software, like an operating system, that provides services to layered software. When discussing software, platform independence implies the software can be run on any computer. OpenGIS Guide
platform The entity of the Technical Reference Model that provides common processing and communication services that are provided by a combination of hardware and software and are required by users, mission area applications, and support applications. TAFIM 3.0
platform The objects, structure, vehicle, or base upon which a remote sensor is mounted. USIGS/CDM-A
platform internal interface (PII) The interface between application platform service components within that platform. IEEE P1003.0
platform profile A profile whose focus is on functionality and interfaces for a particular type of platform, which may be a single processor shared by a group of applications or a large distributed system with each application dedicated to a single processor. IEEE P1003.0
platform, imagery The space, air, land, or seaborne host for imagery sensors (e.g., "U2-R", "C-130"). USIS 95
Platonic year See great year. HDBK-850
plot (JCS) 1. A map, chart, or graph representing data of any sort. 2. To represent on a diagram or chart the position or course of a target in terms of angles and distances from known positions; locate a position on a map or chart. 3. The visual display of a single geographical location of an airborne object at a particular instant of time. 4. A portion of a map or overlay on which are drawn the outlines of the areas covered by one or more photographs. See also master plot. HDBK-850
plot map See photo index. HDBK-850
PLOTSHEET Imagery exploitation reporting tool that is a gateway for data input on precise reporting locations of ships, aircraft, etc., into an imagery exploitation support data base. USIS 95
plotting chart 1. (JCS) A chart designed for the graphical processes of navigation. 2. A chart designed primarily for plotting and dead reckoning or lines of position from celestial observations or radio aids. Relief, culture, and drainage are shown as necessary. HDBK-850
plotting scale The relationship of the size of the compilation to the size of the ground area it represents. HDBK-850
plug and play {DII COE} The ability for a COE-derived system to be scaled by the addition/removal of hardware or software components. To have the property of "plug and play," the system must be able to reconfigure itself automatically after component addition/removal with required human intervention limited to no more than a system power down or reboot. DII COE IRTS
plumb bob A conical device, usually of brass and suspended by a cord, by means of which a point can be projected vertically into space over relatively short distances. HDBK-850
plumb line 1. The line of force in the geopotential field. The continuous curve to which the direction of gravity is everywhere tangential. 2. A cord with a plumb bob at one end for determining the direction of gravity. HDBK-850
plumb point See photograph nadir. HDBK-850
plunge See transit, definition 3. HDBK-850
plus angle See angle of elevation. HDBK-850
plus declination See declination, definition 3. HDBK-850
plus distance Fractional part of 100 feet used in designating the location of a point on a survey line as "4 + 47.2," meaning 47.2 feet beyond Station No. 4 or 447.2 feet from the initial point, measured along a specified line. See also plus station. HDBK-850
plus point An intermediate point on a traverse course located by a plus distance from the beginning of the course. HDBK-850
plus sight See backsight. HDBK-850
plus station An intermediate point on a traverse, not at an even tape length distance from the initial point. See also plus distance; taping station. HDBK-850
point A 0[zero]-dimensional geometric primitive. CEN/TC 287
point A position on a reference system determined by a survey. See also amphidromic point; angle point; annex point: antisolar point; astrogravimetric points; cardinal points; check point; control point; datum point; detail points; distant points; fix; image point; initial point; intercardinal point; map point; middle point; nodal point; orientation point; pass point; plus point; principal point; sublunar point; subsatellite point; subsolar point; substellar point; tie point; turning point; wing point; witness point. HDBK-850
point anomaly The value of the gravity anomaly at a specific location as observed or predicted. HDBK-850
point base A manuscript which contains radial centers, picture points, pass points, control points, and tie points from the photographs used in the radial triangulation method. HDBK-850
point feature An object whose location can be described by a single set of coordinates. HDBK-850
point marker A device used for identifying points on diapositives by either marking a small hole in the emulsion or marking a small ring around the detail point itself Also called snap marker. See also point-transfer device. HDBK-850
point of certainty In a simple two-point intersection problem, that point where the two intersecting rays cross and the point is confirmed by the intersection of a third or check ray passing through the same point. HDBK-850
point of compound curvature (PCC) The point on a line survey where a circular curve of one radius is tangent to a circular curve of a different radius, both curves lying on the same side of their common tangent. HDBK-850
point of contact Any level surface along a terrain profile recorder (TPR) flight line that can be flown over both before and after the changing or adjustment of a TPR positional camera magazine, a chart roll, or a recording pen. HDBK-850
point of curvature (PC) The point in a line survey where a tangent ends and a circular curve begins. See also point of tangency. HDBK-850
point of cusp The point of tangency of two curves, the direction of the extension of said curves being of opposite sign; such as the vertex of a Y of a railroad track or a point on the edge of a convex-concave lens. May also be applied to the point of tangency of a straight line and a curve where the direction of extension of the line and curve are of opposite sign. HDBK-850
point of inflection The point at which a reversal of direction of curvature takes place. HDBK-850
point of intersection (Pl) The point where the two tangents of a circular curve meet. Also called vertex of curve. HDBK-850
point of origin See initial point. HDBK-850
point of reverse curvature (PRC) The point of tangency common to two curves, the curves lying on the opposite side of the common tangent. HDBK-850
point of symmetry The point in the focal plane of a camera about which all lens distortions are symmetrical. If the lens were perfectly mounted, the point of symmetry would coincide with the principal point. HDBK-850
point of tangency (PT) The point in a line survey where a circular curve ends and a tangent begins. The point of tangency and point of curve are both points of tangency, their different designations being determined by the direction of progress along the line; the point of curvature is reached first. HDBK-850
point of vertical curve (PVC) The point of change from a line of uniform slope to a vertical curve. HDBK-850
point of vertical intersection (PVI) The point of intersection of two lines, each having different uniform slopes. HDBK-850
point of vertical tangent (PVT) The point of change from a vertical curve to a line of uniform slope. HDBK-850
point position (Doppler) The geocentric or geodetic position of a point determined from satellite tracking data by a Doppler receiver and the satellite(s) ephemerides. HDBK-850
point position data (PPD) The collective result of an analytical triangulation effort that provides evaluated geodetic positions of photoidentifiable ground points or reseau intersections. These positions are the result of an evaluated adjustment of the points to a specific mathematical surface and are expressed in terms of latitude, longitude, elevation, and positional accuracy for each point. HDBK-850
point positioning (surveying) The process of establishing independent survey position. See also short arc; short arc geodetic adjustment; translocation. HDBK-850
Point Positioning Data Base (PPDB) A deployable set of geodetically controlled photographs with associated parameters, indices and application software. Each PPDB contains a series of stereo models covering a specified geographic area and an accompanying reference manual with software disks to be used by the Analytical Photogrammetric Positioning System (APPS). NIMA LOP
point target A target with an area defined by a center point, a major and minor axis, and a target azimuth. Each point target will be described by its Installation or Facility Identification Elements (IIE/FIE) which include BE number, Geographic Coordinates, Target Name, Country Code, and for FIE, Suffix and Category Code. See also target. USIS 2-1.1
point the instrument Turning the survey instrument to where the cross hairs (vertical, horizontal, or both) are accurately aligned with the target. HDBK-850
point-designation grid (JCS) A system of lines having no relation to the actual scale or orientation, drawn on a map, chart, or air (aerial) photograph, dividing it into squares so that points can be more readily located. HDBK-850
pointer (digital) The address of a record or other data groupings contained in another record. HDBK-850
pointing 1. (mensuration) Placing the reticle or index mark of a precision measuring instrument, such as a comparator, within the symmetrical center or center of gravity of a point being measured to determine its position relative to the position of other points in some system of coordinates. 2. (stereocompilation) A general term applied to the movement of the tracing table of a stereoplotting instrument to specific control and/or picture points on the datum during orientation of a stereomodel. 3. See line of sight, definition 2. HDBK-850
pointing accuracy The exactness, in surveying or photogrammetry, with which the line of sight or floating mark can be directed toward a target or image point. HDBK-850
pointing errors Errors which reflect the accuracy with which the floating mark of a stereoplotting system can be located on a sharp model point. These errors generally follow a more or less random distribution but show a systematic trend with progressive working time on the instrument due to eye fatigue and its effect on stereoscopic perception. HDBK-850
pointing line See line of collimation. HDBK-850
point-in-polygon A geographic information system (GIS) routine which assesses whether a point falls within a polygon. HDBK-850
point-matching method (rectification) The technique of utilizing an autofocus rectifier for tilt removal by the manual matching of projected image points to those plotted in their correct horizontal position on a film templet. HDBK-850
Point-to-Point Protocol (PPP) A protocol which encapsulates common network-layer protocols in specialized packets to pass through certain network commands. Multimedia
point-transfer device A stereoscopic instrument used to make corresponding image points on overlapping photographs. Also called transcriber. See also point marker. HDBK-850
polar axis The primary axis of direction in a system of polar or spherical coordinates. HDBK-850
polar bearing In a system of polar or spherical coordinates, the angle formed by the intersection of the reference meridional plane and the meridional plane containing the point. HDBK-850
polar chart 1. A chart of polar areas. 2. A chart on a polar projection. The projections most used for polar charts are the gnomonic, stereographic, azimuthal equidistant, transverse Mercator, and modified Lambert conformal. HDBK-850
polar circle Either the Arctic Circle (north polar circle) or the Antarctic Circle (south polar circle) . HDBK-850
polar coordinates (JCS) 1. Coordinates derived from the distance and angular measurements from a fixed point (pole). 2. In artillery and naval gunfire support, the direction, distance, and vertical correction from the observer/spotter position to the target. HDBK-850
polar diameter The diameter of the Earth between the poles. HDBK-850
polar distance Angular distance from a celestial pole; the arc of an hour circle between a celestial pole, usually the elevated pole, and a point on the celestial sphere, measured from the celestial pole through 180. See also codeclination. HDBK-850
polar grid A grid system utilized for aerial navigation in the polar regions. It consists of a rectangular grid with x- and y-axes aligned with the 0 - 180 and the 90E - 90W meridians respectively. When plotted on a transverse Mercator map projection of the polar regions, it represents a system of transverse meridians and parallels whose poles are at the intersections of the Equator and the 0 - 180 meridian. HDBK-850
polar map projection A map projection centered on a pole. HDBK-850
polar motion See variation of the pole. HDBK-850
polar orbit An Earth satellite orbit that has an inclination of about 90 and, hence, passe' over the Earth's poles. HDBK-850
polar orthographic map projection A map projection having the plane of the projection perpendicular to the axis of rotation of the Earth (parallel with the plane of the Equator); in this projection, the geographic parallels are full circles, true to scale, and the geographic meridians are straight lines. HDBK-850
polar planimeter An instrument used in measuring areas from a drawing. The instrument rotates about a pole, hence its name. HDBK-850
polar radius The radius of the Earth measured along its axis of rotation. HDBK-850
polar satellite Any satellite that passes over the north and south poles of the Earth; i.e., one that has an inclination of about 90 with resp'ct to the Earth's Equator. HDBK-850
polar stereographic map projection A stereographic projection having the center of the projection located at a pole of the sphere. HDBK-850
Polaris The second-magnitude star, Alpha, in the constellation Ursa Minor (Little Dipper). Also called North Star; polestar. HDBK-850
Polaris correction A correction to be applied to the observed altitude of Polaris to obtain the latitude. HDBK-850
polarization (optics) The act or process of modifying light in such a way that the vibrations are restricted to a single plane. According to the wave theory, ordinary (unpolarized) light vibrates in all planes perpendicular to the direction of propagation. On passing through or contacting a polarizing medium (such as Polaroid or a Kerr cell) ordinary light becomes plane polarized, that is, its vibrations are limited to a single plane. HDBK-850
polarization filter Any of the manufactured plastic fibers which plane polarizes ordinary light when it passes through the filter. Usually identified by a trade name. HDBK-850
polastrodial A mechanical counter for determining the azimuth and altitude of Polaris at any time. HDBK-850
pole 1. Either of the two points of intersection of the surface of a sphere or spheroid and its axis. 2. The origin of a system of polar coordinates. See also average terrestrial pole; celestial pole; depressed pole; ecliptic pole; elevated pole; fictitious pole; galactic pole; geomagnetic pole; magnetic pole; north geographical pole; north geomagnetic pole; north magnetic pole; oblique pole; south geographical pole; south geomagnetic pole; south magnetic pole; terrestrial pole; transverse pole. HDBK-850
pole of the Milky Way The pole in the galactic system of coordinates. HDBK-850
polestar See Polaris. HDBK-850
polhody A chart depicting the motion of the terrestrial pole as a function of time. See also variation of the poles. HDBK-850
policy A set of rules related to a particular purpose. A rule can be expressed as an obligation, a permission or a prohibition. Not every policy is a constraint. Some policies represent an empowerment. RM-ODP
political intelligence Intelligence concerning foreign and domestic policies of governments and the activities of political movements. USIS 95
polyart A plastic based printing substrate with excellent wet strength. HDBK-850
polychrome See multicolor. HDBK-850
polyconic chart A chart on the polyconic map projection. HDBK-850
polyconic map projection A map projection having the central geographic meridian represented by a straight line, along which the spacing for lines representing the geographic parallels is proportional to the distances between the parallels; the parallels are represented by arcs of circles which are not concentric, but whose centers lie on the line representing the central meridian, and whose radii are determined by the lengths of the elements of cones which are tangent along the parallels. All meridians except the central ones are curved. The projection is neither conformal nor equal area, but it has been widely used for maps of small areas because of the ease with which it can be constructed. HDBK-850
polygon Thematically common areas composed of contiguous faces. HDBK-850
polygon A closed geometrical figure defining a directed search area region regarding probable future activity; in imagery collection it re'ers to a sensor's future target acquisitions. USIS 95
polygonization The process of connecting together linear feature information to form polygons. HDBK-850
polyhedric projection A projection used for a large-scale topographic map whereby a small quadrangle on the spheroid is projected onto a plane trapezoid. Scale is made true either on the central meridian or along the sides. HDBK-850
polymedia In computing, this term refers to a more advanced and highly sophisticated multimedia system used in defense, industrial, or medical fields. Polymedia computer systems use supercomputers to format data to provide the user with immediate calculations for real-time animation or simulation. (Prentice Hall) Multimedia
Porro prism A prism that deviates the axis 180 and inverts the image in the plane in which the reflection takes place. It may be described as two right-angle prisms cemented together. HDBK-850
Porro-Koppe principle The principle applied in some photogrammetric instruments to eliminate the effect of camera-lens distortion. The photographic positive or negative is observed through a lens or optical system identical in distortion characteristics to the camera objective which made the original exposure. In effect, this method of observation is a reverse use of the camera, with the focal plane becoming the object which is imaged at infinity by parallel bundles of rays emerging from the lens. The chief ray of each bundle assumes its correct direction, and the cone of rays is identical to that whose vertex was the incident node of the camera lens at the instant of exposure. The parallel bundles may be observed by means of a telescopic system focused at infinity and made rotatable about the incident node of the lens. This method of eliminating lens distortion is utilized in photogrammetric instruments of both the monoscopic type, such as the photogoniometer, and the stereoscopic type used for stereoplotting. HDBK-850
port plan A special-purpose large-scale map of a port area showing piers, railroad extensions, repair facilities, pilot office, customhouse, and other applicable nonnavigational features. HDBK-850
portability {DII COE} The degree to which system components may be transferred from one hardware or software environment to another (IEEE STD 610.12). High portability means that the transfer occurs with minimal or no modifications. For example, a COE segment which was originally developed on a Solaris platform that can be executed correctly on a Hewlett Packard or Silicon Graphics platform by rebuilding the segment without modifying the source code is highly portable. DII COE IRTS
portability The ease with which a system or component can be transferred from one hardware or software environment to another. Synonym: transportability. [IEEE 610.12] IEEE 610-1990
portability (application software) The ease with which application software and data can be transferred from one application platform to another. IEEE P1003.0
portable automatic tide gage A small automatic tide gage, designed for use where a short series of observations is necessary for the reduction of soundings to a common datum. HDBK-850
Portable Operating System Interface for Computer Environments (POSIX) This standard defines a standard operating system interface and environment to support application portability at the source code level. Variants: Portable Operating System Interface for UNIX (POSIX); Portable Operating System Interface Standard for UNIX; Portable Operating System for Information Exchange; Portable Operating System Interface; Portable Operating System Interface standard (IEEE); Portable Operating System Interface eXtension. IEEE POSIX 1988
Portable Operating System Interface for Computer Environments (POSIX) An IEEE standard operating-system interface defining the external characteristics and facilities required to achieve the portability of applications at the source-code level. Variants: Portable Operating System Interface for UNIX (POSIX); Portable Operating System Interface Standard for UNIX; Portable Operating System for Information Exchange; Portable Operating System Interface; Portable Operating System Interface standard (IEEE); Portable Operating System Interface eXtension. TAFIM 3.0
Portable Operating System Interface for UNIX (POSIX) A set of IEEE and ISO standards that define an interface between programs and operating systems. By designing their programs to conform to POSIX, developers have some assurance that their software can be easily ported to POSIX-compliant operating systems. This includes most varieties of UNIX as well as Windows NT. Variants: Portable Operating System Interface for Computer Environments (POSIX); Portable Operating System Interface Standard for UNIX; Portable Operating System for Information Exchange; Portable Operating System Interface; Portable Operating System Interface standard (IEEE); Portable Operating System Interface eXtension. PC Webopaedia
porting The process by which a software application is made operational on a computer architecture different from the one on which it was originally created. TAFIM 3.0
portrayal A representation of geographic information to humans. ISO/TC 211
portrayal element An element for presentation of a feature graphically or otherwise. ISO/TC 211
posigrade orbit A posigrade orbit has an inclination less than 90 degrees. An orbit inclined more than 90 degrees is a retrograde orbit. USIS 95
position 1. Data which define the location of a point with respect to a reference system. 2. The place occupied by a point on the surface of the Earth or in space. Also called place. 3. The coordinates which define the location of a point on the geoid or spheroid. 4. A prescribed setting (reading) of the horizontal circle of a direction theodolite which is to be used for the observation on the initial station of a series of stations which are to be observed. Also called circle position. See also adjusted position; apparent position; astrometric position; astronomic position; celestial fix; celestial line of position; circle of position; convergent position; electronic line of position; field position; fix; geocentric station position; geodetic position; geographic position; line of position; mean position; point position; point positioning; precise installation position; preliminary position; relative position; supplemental position; transverse position; true position. HDBK-850
position angle See parallactic angle, definition 1. HDBK-850
position plotting sheet A blank chart, usually on the Mercator projection, showing only the graticule and a compass rose, so that the chart can be used for any longitude. See also universal plotting sheet. HDBK-850
positional accuracy The primary quality parameter indicating accuracy of geographic position within a geographic subset compared to its nominal ground. CEN/TC 287
positional accuracy (cartography) A term used in evaluating the overall reliability of the positions of cartographic features on a map or chart relative to their true position, or to an established standard. HDBK-850
positional camera photography Photography obtained with a camera aligned with the TPR radar beam, used for correlation and transfer of recorded vertical data to the cartographic photography. HDBK-850
positional error (cartography) The amount by which a cartographic feature fails to agree with its true position. HDBK-850
positioning camera A camera used for correlation purposes in the airborne profile recorder system. It is mounted on the radar antenna and records the area illuminated by the radar beam. HDBK-850
positive In photography, an image on film, plate or paper having approximately the same total rendition of light and shade as the original subject. HDBK-850
positive A backlighted image in which the tones are proportional to the brightness of a true scene. See Negative. USIS 95
positive altitude Angular distance above the horizon. HDBK-850
positive deflection angle See deflection angle. HDBK-850
positive forming In relief model making, forming over a positive mold. HDBK-850
positive lens A lens that converges a beam of parallel light rays to a point focus. Also called converging lens; convex lens. HDBK-850
positive mold The cast pulled from a negative mold when making a relief model. HDBK-850
POSIX Standardized Profile (POSIX SP) A standardized profile that specifies the application of certain POSIX base standards in support of a class of applications and need not require any departure from the structure defined by the reference model for POSIX systems in this guide. IEEE P1003.0
postcondition A predicate that a specification requires to be true immediately after the occurrence of an action. RM-ODP
potential A scalar function, the gradient of which results in a vector field. Use of the scalar function simplifies investigation and description of the phenomenon considered. Used extensively for magnetic, gravitational, and gravity field investigations. In celestial mechanics and geodesy, the negative of the potential, sometimes called the force function, is usually employed. See also disturbing potential; gravitational potential. HDBK-850
potential disturbance See disturbing potential, definition 1. HDBK-850
potential of disturbing masses See disturbing potential, definition 1. HDBK-850
potential of random masses See disturbing potential, definition 1. HDBK-850
power of a lens See diopter; magnification. HDBK-850
power of telescope (surveying) The magnification of a telescope when focused at infinity. HDBK-850
power set of domains A domain containing all possible sets of elements taken from a given domain. NOTE - For example, given a domain D, we can take all possible sets of elements from D to form another domain called the power set of D (sometimes adopted as 2D) which we will denote as Sets(D). A list of elements from D can similarly be denoted as Lists(D). If the arrays are limited to n elements we shall denote it as Lists(D,n). ISO/TC 211
practice A recommended implementation or process that further clarifies the implementation of a standard or a profile of a standard. [VISP (Video Imagery Standards Profile)]. JTA 2.0
Pratt-Hayford theory of isostasy A theory of isostatic compensation which assumes that every topographic excess or defect of mass is compensated by an equal and opposite defect or excess, evenly distributed immediately below it between ground level or sea bottom level and a fixed depth, called the depth of compensation, commonly 113.7 km. Also called fermenting dough theory. See also Airy theory of isostasy. HDBK-850
precedence Reflection o' the originator's determination of the relative importance of the message. Precedence determines the required speed of service and its associated message handling by the recipient(s). [DISA/D2] DISA CFS
precession Change in the direction of the axis of rotation of a spinning body, as a gyroscope, when acted upon by a torque. The direction of motion of the axis is such that it causes the direction of spin of the gyroscope to tend to coincide with that of the impressed torque. See also drift; general precession; planetary precession; topple; topple axis; total drift. HDBK-850
precession in declination The component of general precession along a celestial meridian, amounting to about 20.0" of arc per year. HDBK-850
precession in right ascension The component of general precession along the celestial equator, amounting to about 46.1" of arc per year. HDBK-850
precession of the equinoxes The conical motion of the Earth's axis about the vertical to the plane of the ecliptic, caused by the attractive force of the Sun, Moon, and other planets on the equatorial protuberance of the Earth. See also general precession. HDBK-850
Precise Bathymetric Navigation Zone Charts (PBNZCs) Charts depicting highly detailed underwater topography in the form of bathymetric curves. Detailed multibeam/swath bathymetry allow submarines to precisely fix their positions from bottom contour matching. Also called Bathymetric Recovery Area Charts (BRACs). HDBK-850
precise ephemeris Coordinates and velocity of an artificial satellite, computed for uniform time intervals from data acquired from a worldwide tracking network. The ephemeris is computed from observations taken from many stations spaced worldwide and adjusted together by least squares methods for maximum accuracy. See broadcast ephemeris; ephemeris; Navy Navigation Satellite System. HDBK-850
precise installation position (PIP) Geodetic coordinates of installation reference points reflecting their maximum possible refinement by utilizing all intelligence sources and optimum computer techniques of analytical area adjustment. HDBK-850
precise level An instrument designed specifically for obtaining precise results by direct leveling techniques. It is essentially the same as an engineer's level except that it contains micrometer screws for more precise leveling of the instrument and contains a prism arrangement whereby the level bubble can be observed simultaneously with the rod reading. HDBK-850
precise leveling rod A rod used for precise leveling. The graduations are on an Invar ribbon which is maintained under constant tension and which, for all practical purposes, eliminates the need for correcting for changes in length. These rods are usually graduated in whole and fractional meters. The back side of the rod is graduated in feet and tenths of feet. Also called Invar leveling rod; meter rod; Molitar precise leveling rod; National Geodetic Survey first-order leveling rod. HDBK-850
precise radar significant location (PRSL) The horizontal and vertical values derived for a selected ground feature that is radar significant. The return may be either positive or negative. HDBK-850
precision The closeness with which repeated measurements made under similar conditions are grouped together. NOTE: Precision is affected only by the random errors in the measuring process. Accuracy is affected by precision and unknown and/or systematic errors. HDBK-850
precision Refers to the level of measurement and exactness of description in a GIS database. Precise locational data may measure position to a fraction of a unit. Precise attribute information may specify the characteristics of features in great detail. It is important to realize, however, that precise data - no matter how carefully measured - may be inaccurate. Surveyors may make mistakes or data may be entered into the database incorrectly. Therefore, a distinction is made between precision and accuracy . OpenGIS Guide
precision altimeter A sensitive aneroid barometer. In surveying, it will produce results accurate to within a meter only when the two-base method is carefully applied. See also two-base method. HDBK-850
Precision Automatic Photogrammetric Intervalometer (PAPI) System Automatic intervalometer utilizing radar in determining interval for desired aerial photography forward lap. HDBK-850
precision camera A relative term used to designate any camera capable of giving high resolution and dimensional results of a high order of accuracy. HDBK-850
precision depth recorder A device which records sounding information on electrosensitive paper for depths up to 6,000 fathoms. It provides a trigger to the sonar and performs a time measuring function. HDBK-850
precondition A predicate that a specification requires to be true for an action to occur. RM-ODP
predicate A logical function that returns only True or False as values. CEN/TC 287
predicted collection The predicted results of specific collection operations based on planned tasking for sensing on the next mission, sortie, or pass, as appropriate. USIS 95
predominant height (JCS) In air reconnaissance, the height of 51 percent or more of the structures within an area of similar surface material. HDBK-850
preferred datum A geodetic datum selected as a base for consolidation of local independent datums within a geographical area. Also called major datum. HDBK-850
preferred grid 1. The grid designated by DoD for production of new maps, charts, and digital geographic data; and shown on the "Index to Preferred Grids, Datums, and Ellipsoids Specified for New Mapping." 2. The grid preferred by DMA [NIMA] for production of new maps and charts. HDBK-850
preliminary Not of the desired accuracy and precision, and adopted for temporary use with the proviso of later being superseded. HDBK-850
Preliminary Design Review (PDR) A review conducted prior to commencing the detailed design process to assure that the approach is feasible and sound from a design, development, test, and activation point of view. HDBK-850
preliminary edition See provisional edition. HDBK-850
preliminary elevation An elevation arrived at in the office after the index, level, rod, and temperature corrections have been applied to the observed differences of elevation and new elevations have been computed. HDBK-850
preliminary orientation An initial, rough orientation of projectors prior to accomplishing relative orientation of a stereomodel. It is the approximate leveling and scaling of the instrument frame and projectors, based on the best estimate of what their ultimate orientations are assumed to be. HDBK-850
preliminary position In the adjustment of triangulation, the term preliminary is applied to geographic positions derived from selected observations for use in forming latitude and longitude condition equations. HDBK-850
preliminary survey The collection of survey data on which to base studies for a proposed project. See also reconnaissance survey. HDBK-850
preliminary triangle In the adjustment of triangulation, the term preliminary is applied to triangles derived from selected observations for use in forming latitude and longitude condition equations. HDBK-850
preparing activity The DOD activity or the civilian agency responsible for the preparation, coordination, issuance, and maintenance of standardization documents. [DOD 4120.3-M] DISA CFS
Pre-Planned Product ImprovIment (P3I) A P3I is a planned, future evolutionary improvement for a system currently under development. Program offices generally identify, plan foI, and program P3I for that technology not currently attainable or to provide interface with other systems not yet defined or fielded. [DISA/D4] DISA CFS
preprocessing Preliminary transformation of raw data required to facilitate further cartographic processing. HDBK-850
prepunch register system A method in which a system of precisely located holes are punched in the margins of map or chart materials (such as films, vinyls, etc.) prior to their actual use. Exact register of materials can be accomplished by placing register studs (small plastic or metal pins) through the holes, thereby assuring exact register of detail. See also register marks. HDBK-850
prescribed grid The grid that is locally prescribed by the country of origin of military commander. HDBK-850
prescriptive architecture (TAP) A C4ISR Architecture description that reflects the programmed baseline architecture with recommended changes. NIMA/AR
presentation graphics Pictorial representations of the relationships between variables (graphs and charts) or representations of systems (diagrams, schematics, and graphical renditions). [HCI Style Guide] DISA CFS
presentation layer The sixth layer of the OSI Reference Model. It allows an application to properly interpret the data being transferred. TAFIM 3.0
Presentation Manager A graphical user interface developed by IBM for use with the OS/2 operating system. HDBK-850
Pre-Ship Readiness Review (PSR) A review under the verification phase of [NIMA's] modernization program (DPS). PSR examines segment factory testing, planned testing activities, and production center readiness to determine when to ship DPS equipment from the contractor to the production centers. HDBK-850
President's Daily Brief A magazine-quality document and briefing on the most significant intelligence issues for the President. USIS 95
press plate See plate. HDBK-850
press proof A lithographed impression taken from among the first copies run on the press and used for checking purposes. Also called press pull. HDBK-850
press pull See press proof. HDBK-850
pressure altimeter See barometric altimeter. HDBK-850
pressure altitude (JCS) An atmospheric pressure, expressed in terms of altitude which corresponds to that pressure in the standard atmosphere. See also altitude. HDBK-850
pressure gage A tide gage that is operated at the bottom of the body of water being gaged and which records tidal height changes by the difference in pressure due to the rise and fall of the tide. HDBK-850
primary See primary body. HDBK-850
primary aim point The point at which the imaging system is actually aiming during an imaging operation. USIS 95
primary bench mark A bench mark close to a tide station to which the tide staff and tidal datum originally were referenced. HDBK-850
primary body The celestial body or central force field about which a satellite or other body orbits, or from which it is escaping, or towards which it is falling. Also called primary. HDBK-850
primary circle See primary great circle. HDBK-850
primary compilation A specially prepared matte plastic material used to depict sounding data corrected to true depths in bathymetric compilations. HDBK-850
primary great circle A great circle used as the origin of measurement of a coordinate; particularly such a circle 90 from the poles of a system of spherical coordinates, as the Equator. Also called fundamental circle; primary circle. HDBK-850
primary grid The major, or principal grid on map or chart. HDBK-850
primary key A key that uniquely identifies a row of data in a data base. HDBK-850
primary key The primary key of an entity, which is required, is one or more attributes whose value uniquely identifies every instance of the entity. USIGS/CDM-A
primary quality parameter The quality parameter applicable to all geographic data. CEN/TC 287
primary row A single row of attribute data associated with a simple feature. HDBK-850
primary station See main scheme station. HDBK-850
primary tide station A place at which continuous tide observations are made over a number of years to obtain basic tidal data for the locality. HDBK-850
prime fictitious meridian The reference meridian (real or fictitious) used as the origin for measurement of fictitious longitude. HDBK-850
prime grid meridian The reference meridian of a grid. In polar regions it is usually the 180 - 0 geographic meridian, used as the origin for measuring grid longitude. HDBK-850
prime inverse meridian See prime transverse meridian. HDBK-850
prime meridian The meridian of longitude 0, used as the origin for measurement of longitude. The meridian of Greenwich, England, is almost universally used for this purpose. HDBK-850
prime meridian (UCDM Entity: "PRIME-MERIDIAN") Meridian from which the longitudes of other meridians are quantified. USIGS/CDM-A
prime oblique meridian The reference fictitious meridian of an oblique graticule. HDBK-850
prime transverse meridian The reference meridian of a transverse graticule. Also called prime inverse meridian. HDBK-850
prime vertical See prime vertical circle. HDBK-850
prime vertical circle The vertical circle through the east and west points of the horizon. It may be true, magnetic, compass, or grid, depending upon which east or west points are involved. Also called prime vertical. HDBK-850
prime vertical plane The plane perpendicular to the meridian plane (astronomic or geodetic) containing the normal. The intersections of the astronomic prime vertical plane with the horizon are the east and west points. Also called east point. HDBK-850
primitive (digital mapping) The lowest level of attribution. HDBK-850
primitive The smallest spatial component of which all features are composed. EXAMPLE - there are 3 geometric primitives (nodes, edges, faces) and one cartographic primitive (text). ISO/TC 211
principal axis See optical axis. HDBK-850
principal distance 1. The perpendicular distance from the internal perspective center to the plane of a particular finished negative or print. This distance is equal to the calibrated focal length corrected for both the enlargement or reduction ratio and the film or paper shrinkage or expansion. It maintains the same perspective angles at the internal perspective center to points on the finished negative or print, as existed in the taking camera at the moment of exposure. This is a geometrical property of each particular finished negative or print. Also called effective focal length. 2. (multiplex) The perpendicular distance from the internal perspective center of the projector lens to the plane of the emulsion side of the diapositive. HDBK-850
principal focus See focus. HDBK-850
principal line The trace of the principal plane upon a photograph (e.g., the line through the principal point and the nadir point). HDBK-850
principal meridian 1. The meridian extended from an initial point, upon which regular quarter-quarter section, section, and township corners have been or are to be established. See also auxiliary guide meridian; guide meridian. 2. (photogrammetry) See principal point. HDBK-850
principal parallel (JCS) On an oblique photograph, a line parallel to the true horizon and passing through the principal point. HDBK-850
principal plane 1. (JCS) (photogrammetry) A vertical plane which contains the principal point of an oblique photograph, the perspective center of the lens, and the ground nadir. 2. (optics) A plane through a principal point and perpendicular to the optical axis. See also axis of homology; axis of tilt; ground parallel; ground trace; horizon trace; isometric parallel; line of constant scale; line of equal scale; photograph meridian; photograph parallel; principal line; principal meridian; principal parallel: vanishing line; vanishing point. HDBK-850
principal planets The larger bodies revolving about the Sun in nearly circular orbits. The known principal planets, in order of their distance from the Sun, are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. HDBK-850
principal point 1. (JCS) (photogrammetry) The foot of the perpendicular to the photo plane through the perspective center. Generally determined by intersection of the lines joining opposite collimating or fiducial marks. [If the fiducial marks are not visible on the photograph, the principal point may be found by drawing diagonals between opposite corners or by measuring one-half the distance along each side of the photograph and connecting these marks in the same manner as fiducial marks, or by reseau marks.] Also called indicated principal point. See also photograph center. 2. (calibrated) The center of radial lens distortion, usually given as x- and y- distances from indicated principal point. HDBK-850
principal scale (JCS) In cartography, the scale of a reduced or generating globe representing the sphere or spheroid defined by the fractional relation of their respective radii. Also called nominal scale. See also scale. HDBK-850
Principal Staff Assistant (PSA), OSD The PSAs represent the user community in the functional area under their direction on acquisition and requirements matters. The OSD PSAs are the Undersecretaries of Defense (USDs), the Director of Defense Research and Engineering (DDR&E), the Assistant Secretaries of Defense (ASDs), the Director, Operational Test and Evaluation (DOT&E), the General Counsel of the Department of Defense (GC, DoD), the Inspector General of the Department of Defense (IG, DoD), the Assistants to the Secretary of Defense (ATSDs), and the OSD Directors or equivalents, who report directly to the Secretary or the Deputy Secretary of Defense. DoDD 5000.1
principal station See main scheme station. HDBK-850
principal vertical (JCS) On an oblique photograph, a line perpendicular to the true horizon and passing through the principal point. HDBK-850
principal vertical circle The vertical circle through the north and south points of the horizon, coinciding with the celestial meridian. HDBK-850
principal-distance error In a stereoplotting system, an instrument error resulting from improper calibration of the aerial camera, diapositive printer, or projector. The error is of little importance in a flat surface model but the effects are increased in proportion to the relief in the model. HDBK-850
principal-point assumption The assumption with respect to approximately vertical photographs that radial directions are correct if measured from the principal point. HDBK-850
principal-point error A personal error in which the principal points in a stereoplotting system are displaced in such a manner that they have unequal x components with a resultant error in vertical scale. Such errors are usually introduced into the system by either improper orientation of the diapositive plate in the printer, in the projector, or both. HDBK-850
principal-point radial A radial from the principal point of a photograph. HDBK-850
principal-point triangulation See radial triangulation. HDBK-850
print A photographic copy made by projection or contact printing from a negative or transparency. See also contact print; diapositive; enlargement; matte print; photographic reduction; projection print; ratio print; rectified print; transformed print. HDBK-850
print A representation of a portion of a frame of imagery that has been produced from a negative or by a softcopy work station. Most prints are prepared on a target of interest on the image. USIS 95
prism A transparent body bounded in part by two plane faces that are not parallel; used to deviate or disperse a beam of light. See also dove prism; horizon prism; index prism; Porro prism; reflecting prism; refracting prism; retrodirective prism; rhomboidal prism; right-angle prism; roof prism; wedge. HDBK-850
prismatic astrolabe An astrolabe consisting of a telescope in a horizontal position, with a prism and artificial horizon attached at its objective end, used for determining astronomic positions. HDBK-850
prismatic compass A small magnetic compass held in the hand when in use and equipped with peepsights and glass prism so arranged that the magnetic bearing or azimuth of a line can be read at the same time that the line is sighted over. HDBK-850
prismatic error That error due to lack of parallelism of the two faces of an optical element, such as a mirror or a shade glass. HDBK-850
Probabilistic Vertical Obstruction Data (PVOD) A file which combines Residual Density Functions with discrete (manmade and natural) vertical obstruction data extracted from Vertical Obstruction Data (VOD), Digital Feature Analysis Data (DFAD), the NIMA Digital Vertical Obstruction File (DVOF), Power Line Data, Digital Cities Data, and intelligence data bases. VOD is a data file containing discrete position and height information of manmade objects and vegetation extending above the terrain. Vertical obstructions include such manmade objects as radio towers, smokestacks, bridges, powerlines, and other objects above minimum elevations specified by cruise missile planners. [PVOD is the replacement for VOD.] NIMA LOP
probability interval See confidence interval. HDBK-850
probable error 1. In a measured value, it is the most probable value of the resultant error in the measurement. This is a plus or minus quantity that may be larger than the resultant error or smaller than the resultant error, and its probability of being larger is equal to its probability of being smaller. 2. The 50 percent error interval based on the bivariate normal distribution function. HDBK-850
procedural interface The methods and procedures employed to establish an interconnection within and between systems/equipment and to transfer information with or between systems/equipment. [CJCSI 6212.01] DISA CFS
process An address space and one or more threads of control that execute within that address space, and their required system resources. IEEE P1003.0
process A general term for any computer operation on data. TAFIM 3.0
Process Action Team A small group of key workers directly from the process in question who are tasked and empowered by management to look at the process and define improvements. [DISA Quality Management Course] DISA CFS
process camera See copy camera. HDBK-850
process color printing (lithography) A technique for the reproduction of a subject or chart in full color rendition, by combining tones of the primary colors, (yellow, magenta, cyan) and black. See also process plates. HDBK-850
process lens A lens for photochemical copying, enlarging, or projection purposes, free from aberrations, usually of low aperture and of symmetrical construction. HDBK-850
process model Provides a framework for identifying, defining, and organizing the functional strategies, functional rules, and processes needed to manage and support the way an organization does or wants to do business - provides a graphical and textual framework for organizing the data and processes into manageable groups to facilitate their shared use and control throughout the organization. [DOD 5000.11-M] DISA CFS
process photography Line and halftone photography in which the resulting negatives and positives are subsequently used in the preparation of press plates. HDBK-850
process plates Two or more color press plates combined to produce other colors and shades. See also color plate; combination plate; process color printing. HDBK-850
processing The act of converting information into a form suitable to the production of intelligence. JPUB 2-0
processing 1. Encompasses the processes, equipment, and capabilities that convert raw collected image data into usable image data or imagery for use in the production process. 2. The manipulation of data from one form to another that does not alter the information content of the data but changes the format, generally from one that is not human readable/usable to a form that is usable. Processing can take place either in an electronic environment such as correlating radar data or in a physical sense such as developing a latent image on film. This definition also includes those direct duplication actions coincident with subsequent reproduction processing to make multiple copies of the original information available; such as making a duplicate (positive or negative) of previously processed film or making a copy of an electronic image available at several sites. USIS 95
processing (photographic) In photography, the operations necessary to produce negatives, diapositives, or prints from exposed films, plates, or paper. USIS 95
Processless Electron Recording Medium (PERM) A hardcopy image produced by a dry process vice the classic wet (photo lab) process. PERM is tinted blue. USIS 95
processor A concept representing the capabilities of an executable piece of code. CEN/TC 287
product A completely specified data set, comprised of a set of profiles; specifically including, the schema, metadata, quality information, reference system, structure primitives, and encoding. ISO/TC 211
product data Data that is either collected in a specific product form or data which is derived from neutral data for a specific application. HDBK-850
Product Generation Segment (PG/S) A segment of NIMA's DPS which will provide the capability to generate both digital products and reproducible materials for hard copy maps and charts. By utilizing digitizing capabilities and graphic workstations, the segment will provide for collection of MC&G data from existing hard copy graphics including maps, charts, and manuscripts. During product generation, the segment will extract appropriate data from the MARK 90 MC&G database to generate required products. In producing color separates for graphic products, PG/S will convert the digital data to graphic symbols, generalize and displace graphic symbols, perform color separation, and generate the reproducible copy. See also MARK 90; Digital Production System (DPS). HDBK-850
product line A set of products that share common attributes (technology, design, parts, manufacturing, processes) grouped to realize economies of scope; but which may have different specific features and functionality required by different sets of customers. DODI 4630.8
product specification A description of the abstract universe and a specification for mapping the abstract universe to a dataset. ISO/TC 211
product specification (UCDM Entity: "PRODUCT-SPECIFICATION") The overarching guidance which specifies the form and content of a product. USIGS/CDM-A
production Conversion of information into intelligence through the integration, analysis, evaluation, and interpretation of all-source data and the preparation of intelligence products in support of known or anticipated user requirements. JPUB 1-02
Production Management Segment (PM/S) Segment of NIMA's DPS which will incorporate the MARK 85 Data Integration Segment to provide a total production planning and management capability using the MARK 90 production processes. This segment will perform requirements, definition, long-range planning, program development, production scheduling, and status reporting. See also MARK 90; Digital Production System (DPS). HDBK-850
profile leveling The determination of elevations of points at short measured intervals along a definitely located line, such as the center line of a highway. HDBK-850
profile of a standard An extension to a existing, approved standard which further defines the implementation of that standard in order to ensure interoperability. A profile is generally more restrictive than the base standard it was extracted from. [VISP (Video Imagery Standards Profile)] Contrast with profile, standards. JTA 2.0
profile of a standard The tailoring of a standard to satisfy a specified need. Tailoring is accomplished by selecting a subset of the standard or by selecting options within the standard. A profile is selected to apply across an application area of a standard rather than across a single application. Contrast with profile, standards. USIS 95
profile, standards A set of one or more base standards, and, where applicable, the identification of chosen classes, subsets, options, and parameters of those base standards, necessary for accomplishing a particular function. Contrast with profile of a standard. IEEE P1003.0
profile, terrain 1. A vertical section of the surface of the ground, or of underlying strata, or both, along any fixed line. 2. Elevation of the terrain along some definite line. Elevations are measured at a sufficient number of points to enable defining the configuration of the ground surface. HDBK-850
profile, user {DII COE} The subset of the total COE-based functionality that is to be made available to a group of individual operators. Profiles are defined by the security or system administrator to limit what an operator can"access both "n a "need to know" basis and as a way to avoid overwhelming the operator with functions that are not useful for his mission area. DII COE IRTS
Program Executive Officer (PEO) When the Director, DISA, appoints a Program Executive Officer (PEO), that PEO has the authority, responsibility, and accountability for managing assigned programs in a manner consistent with DODD 5000.1, DODI 5000.2, DODD 8120.1, DODI 8120.2, and DISAI 630-230-21. A PEO oversees one or more programs which are generally similar and/or closely related. PEOs review and provide their assessment of any changes in their programs and determines the significance of problems reported by their PM'. PEOs reviews PM's proposed plans and determines the level of risk associated wi'h such plans. PEO's report directly to the Director. [DISA/D4] DISA CFS
Program Manager (PM) A Program Manager (PM) is a person who is directly responsible for managing a particular program, that may have multiple projects under centralized management. A PM has the authority, responsibility, and accountability for managing assigned programs in a manner consistent with DODD 5000.1, DODI 5000.2, DODD 8120.1, DODI 8120.2, and DISAI 630-230-21. Program Managers provide assessments of program cost, schedule, and performance status and risk in all briefings and presentations to higher authorities, actively manage contract performance, and provide assessment of contractor performance. Program Managers normally report directly to a Program Executive Officer (PEO). [DISA/D4] DISA CFS
program, acquisition See acquisition program. DoDD 5000.1
programmed baseline architecture (TAP) A C4ISR Architecture that reflects the capabilities, data exchanges, interfaces, operations concepts and systems expected to be in place based on what has been budgeted and planned for a specific point in time. NIMA/AR
Programmers Hierarchical Interactive Graphics System (PHIGS) An ANSI standard which provides a set of functions for modification of graphics data and the relationships between the graphical data; and the definition, display, and modification of geometrically related objects, and two and three dimensional graphical data. See also Graphic Kernal System. HDBK-850
programming language Artificial language established for expressing computer programs. [HCI Style Guide] DISA CFS
programming language application program interface (API )specification The interface between applications and application platforms traditionally associated with programming language specifications, such as program control, math functions, string manipulation, etc. IEEE P1003.0
progress sketch A map or sketch showing work accomplished. In triangulation and traverse surveys, each point established is shown on the progress sketch, and also lines observed over and base lines measured. In a leveling survey, the progress sketch shows the route followed and the towns passed through, but not necessarily the locations of the bench marks. HDBK-850
progressive motion Motion in an orbit in the usual orbital direction of celestial bodies within a given system. Specifically, motion of a satellite in the same direction to the direction of the primary. Opposite of retrograde motion. HDBK-850
progressive proofs A series of color prints that show the individually separated color printings of a job and their progressive combinations as each color is overprinted. HDBK-850
prohibition A prescription that a particular behavior must not occur. A prohibition is equivalent to there being an obligation for the behavior not to occur. RM-ODP
Project Assignme't Instruction DIA's AIRES-resident exploitation management system; used to prioritize and assign exploitation tasks and to record imagery analyst and manager workloads associated with task accomplishment. USIS 95
Project Manager {DISA} Individuals chartered to conduct business on behalf of DISA who manage all or portions of a fielded system who report to or receive direction from the Communications or Information Systems Managers or their management structure. Project Managers plan and execute preplanned system upgrades and modernization for these fielded systems or subsystems. Within DISA, Project Managers do not report through the Acquisition chain but are still bound by ILS policy. [DISA/D4] DISA CFS
Projected Map Display (PMD) An inflight navigation aid which uses a continuous color or black-and-white sprocketed filmstrip containing chart imagery, projected on a display device and driv'n by the aircraft's comp'ter. The aircraft's position is displayed with correlated chart image to show location and direction actually being flown. HDBK-850
projection 1. (geometry) The extension of lines or planes to intersect a given surface; the transfer of a point from one surface to a corresponding position on another surface by graphical or analytical methods. See also map projection. 2. (photography) The process of placing a negative or positive photograph in a projecting camera and reproducing the image on a screen or on a sensitized photographic medium. 3. (surveying) The extension of a line beyond the points which determine its character and position. The transfer of a series of survey lines to a single theoretical line by a series of lines perpendicular to the theoretical line. In surveying a traverse, a series of measured short lines may be projected onto a single long line, connecting two main survey stations, and the long line is then treated as a measured line of the traverse. See also prolongation. HDBK-850
projection computation The determination, from a set of tables derived from formulas, of the true shape and dimensions of a map projection, for the purpose of constructing such a projection. See also grid computation. HDBK-850
projection distance The distance from the external node of a projection lens to the plane onto which the image is projected. HDBK-850
projection generation The transformation of a spherical surface, such as the earth, to a plane surface. Regardless of the transformation method, there is always some distortion in the plane view. HDBK-850
projection print (JCS) An enlarged or reduced photographic print made by projection of the image of a negative or a transparency onto a sensitized surface. HDBK-850
projection printer An optical device for enlarging or reducing the image of a negative or positive transparency by projecting it onto a sensitized surface. HDBK-850
projection tables Data made available in tabular form for determining a definite relationship which exists between any grid intersection and any adjacent intersection of latitude and longitude lines on the map projection. HDBK-850
projection ticks and crosses Ticks perpendicular to and inside the neatline of a map placed to indicate points through which parallels and meridians would pass if they had been extended. Small cross marks indicate where the lines intersect within the map. HDBK-850
projection transformation The process of changing from one map projection to another map projection. Transformations may involve changes in equations, ellipsoids, scale factors, cone constants, standard lines, standard parallels, origins, central meridians, etc. HDBK-850
projector An optical instrument which throws the image of a negative or print upon a screen or other viewing surface, usually at a larger scale. See also reflecting projector. HDBK-850
projector station The position of a projector unit of a stereoplotter when absolute orientation has been accomplished. This position recreates the conditions existing at the corresponding camera station at the instant of exposure. HDBK-850
prolate ellipsoid of rotation See prolate spheroid. HDBK-850
prolate spheroid An ellipsoid of rotation along the major axis, which is along the axis of earth rotation. Also called prolate ellipsoid of rotation. HDBK-850
prolongation In surveying, a line is prolonged when the last segment of the surveyed line is extended in the same direction as the segment itself. A prolongation of a curve under such a definition of extension would be a line tangent to the curve at the point of extension, although the term frequently is used to mean a continuation along the curvature of the curve. HDBK-850
proof A trial print, produced by any method, for examination or editing, to be marked for necessary corrections or approval. See also color composite; color proof; color proof process; composite; final composite; galley proof; hand proof; OK sheet; press proof; progressive proofs; proofing. HDBK-850
proofing The operation of pulling proofs of plates for proofreading, revising, approval, and other purposes prior to production printing. HDBK-850
proper motion That component of the space motion of a celestial body perpendicular to the line of sight, resulting in th' change of a star's apparent position relative to a coordinate system such as right ascension and declination. This change is expressed as a velocity, such as seconds of arc per century. HDBK-850
property map See cadastral map. HDBK-850
property survey See land survey. HDBK-850
proportionate measurement A measurement that applies an even distribution of a determined excess or deficiency of measurement, ascertained by retracement of an established line, to provide concordant relations between all parts. See also double proportionate measurement; single proportionate measurement. HDBK-850
proposal A description of products/services DISA will provide to a customer at the specified price. If the customer accepts the proposal, a service level agreement (SLA) is negotiated. [DISA WESTHEM} DISA CFS
proposition An observable fact or state of affairs involving one or more entities, of which it is possible to assert or deny that it holds for those entities. RM-ODP
PROTEUS An Army sponsored-advanced technology testbed for the assessment of advanced communications technologies. Provides proof of concepts for evaluation and dissemination of asynchronous transfer mode (ATM) cells to lower echelons. USIS 95
protocol Rules specifying a service. CEN/TC 287
protocol A set of semantic and syntactic rules that determine the behavior of entities that interact. IEEE P1003.0
protocol data unit (PDU) DIS terminology for a unit of data that is passed on a network between simulation applications. (DoD 5000.59-P, "Modeling and Simulation Master Plan," October 1995, authorized by DoD Directive 5000.59, January 4, 1994) JTA 2.0
protocol object An engineering object in a channel that communicates with other protocol objects in the same channel. Protocol objects achieve interaction between engineering objects which are in different clusters, capsules, and nodes. RM-ODP
protocol, network 1. A set of rules governing network functionality. The OSI Reference Model uses sets of communication protocols to facilitate communication between computer networks and their components. [TAFIM 3.0, vol. 4] 2. Hardware and software procedures used to transfer cryptographic, voice, data, and control information between subscriber terminals and switching facilities; line protocol procedures may include synchronization, signaling, supervision, message transmission, error detection, and correction functions. [Joint Pub 6-02.1] DISA CFS
prototype See experimental map; pilot sheet. HDBK-850
provisional edition A map or chart printed and distributed for temporary use with the proviso that it will later be superseded. Also called preliminary edition. HDBK-850
provisional map Any nonofficial map, photo, or other material which is used as a map. It may vary from a highly accurate captured enemy map, which has not been sanctioned for use, to a hastily made drawing or sketch. It is usually a hastily made line map based on aerial photographs, used as a map substitute. HDBK-850
proximity A measure of closeness to a specified point as defined by a user. HDBK-850
proximity analysis Analytical technique used to determine the relationship between a specified point and its neighbors. HDBK-850
proximity search An analytical procedure to identify occurrences of predefined data elements in the neighborhood of a selected point. HDBK-850
pseudoscopic stereo A three-dimensional impression of relief which is the reverse of that actually existing when the positions of a stereo pair of photographs are interchanged. Also called inverted stereo; reverse stereo. See also false stereo. HDBK-850
public specifications Specifications that are available, without restriction, to anyone for implementation, sublicensing, and distribution (i.e., sale) of that implementation. IEEE P1003.0
publication scale See reproduction scale. HDBK-850
Pulkovo 1942 datum The geodetic datum defined at Pulkovo Observatory [St. Petersburg, Russia] using the Krasovsky ellipsoid. HDBK-850
pull up See selection overlay. HDBK-850
pulse Doppler map matching (PDMM) An image matching concept employing a pulse Doppler mapping technique to locate three preselected unique edges within the terrain scene viewed prior to reentry of the vehicle. Edges are defined by differences in radar reflectance. Range and range rate data are obtained from a small elemental area of the terrain illuminated by the antenna beam spot during a fix action. A range/range rate map of the spot area is then correlated against a reference map of the particular edge to provide a range and velocity update to the onboard vehicle inertial measurement unit (IMU). Three such successive fix correlations are executed to enable a trilateration solution of the vehicle's position relative to the target scene by the sensor's computer. Therefore, the IMU can calculate a corrective maneuver prior to impact. HDBK-850
Px64 The ITU-T's international video standard which provides a standard algorithm for video compression and decompression. Formally known as H.261, it was adopted in December 1990. Multimedia
pygmy meter A small cup type current meter for use in low velocity measurements in shallow streams. This meter is used in conjunction with wading rods only. HDBK-850
Pythagorean right-angle inversor A simple device which provides a mechanical solution for linear and angular elements of rectification, thus permitting any enlarger to be made autofocusing provided negative, lens, and easel planes are parallel. HDBK-850
PZS triangle See astronomic triangle. HDBK-850

Last Updated by Mark Owens 7 January 1999.