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Term Definition/Description Source
D log E curve See characteristic curve. HDBK-850
daily aberration See diurnal aberration. HDBK-850
daily inequality See diurnal inequality. HDBK-850
Daily Intelligence Summary A report prepared in message form at the joint force component command headquarters that provides higher, lateral, and subordinate headquarters with a summary of all significant intelligence produced during the previous 24-hour period. The "as of" time for information, content, and submission time for the report will be as specified by the joint force commander. USIS 95
danger line 1. A line drawn on a chart to indicate the limits of safe navigation for a vessel of specific draft. 2. A line of small dots used to draw the navigator's attention to a danger which would not stand out clearly enough if it were represented on the chart solely by specific symbols. HDBK-850
data A representation of facts, concepts, or instructions in a manner suitable for communication, interpretation, or processing by humans or by automatic means. Note: "Data" is plural for datum, but is often used as a collective noun, as in "The data is in this file." [IEEE 610.12] IEEE 610-1990
data acquisition station A ground station used for performing the various functions necessary to control satellite operations and to obtain data from the satellite. HDBK-850
data aggregate A collection of two or more data items that are treated as a unit. [IEEE 610.5] IEEE 610-1990
data bank hierarchy A formalized structure which provides for the organization of data at various quantitative levels; e.g., data bank, data base, file, record, field (element), character, bit. HDBK-850
Data Base Entry Message (DBEM) An electronically disseminated reporting product that contains imagery exploitation target or topic reports for the purpose of updating the National Data Base of Imagery Derived Information (NDBIDI) and other designated data bases within the intelligence community and military operational forces. USIS 2-1.1
data block Information presented on air imagery relevant to the geographical position, altitude, attitude, and heading of the aircraft and, in certain cases, administrative information and information on the sensors employed. USIS 95
data category (layer) Refers to data having similar characteristics being contained in the same data set, eg., roads, rivers. Usually information contained in one data category is related and is designed to be used with other categories. HDBK-850
data chamber The portion of a cartographic aerial camera where ancillary data is recorded along the film margins. Data usually includes time, altitude, frame number, and other information required for identification and correlation purposes. It may include a character data generator block and extensive binary coded information to include aircraft position and camera orientation data. HDBK-850
data compression See Compression. Multimedia
data definition A description of the format, structure, and properties of a data item, data element, or data structure. [IEEE 610.5] IEEE 610-1990
data definition language (DDL) 1. A language for describing the organization of data within a database. Note: In some software, the logical organization is described; in some, both the logical and physical organizations are described. 2. A language used to describe the logical structure of a database. Syn: data description language, database descriptive language; schema definition language; schema language. [IEEE 610.5] IEEE 610-1990
data dictionary Repository of information about the definition, structure, and usage of data. It does not contain the actual data. HDBK-850
data dictionary A collection of entries specifying the name, source, usage, and format of each data element used in a system or set of systems. [IEEE 610.5] IEEE 610-1990
data dictionary A specialized type of database containing metadata that is managed by a data dictionary system; a repository of information describing the characteristics of data used to design, monitor, document, protect, and control data in information systems and databases; an application of data a dictionary system. (DoDD 8320.1-M-1, "Data Element Standardization Procedures," January 15, 1993, authorized by DoD Directive 8320.1, September 26, 1991) JTA 2.0
data element A basic unit of information having a meaning and that may have subcategories (data items) of distinct units and values. [DODD 8320.1] DISA CFS
data element 1. A uniquely named and defined component of a data definition; a data "cell" into which data items (actual values) can be placed. For example, the data element AGE, into which data items 1, 2, ... can be placed. Note: The terms data element and data item are often used interchangeably or with the reverse definitions from those given here. No standard of use exists at this time. 2. A data definition as in (1) that cannot be divided into other individually named data definitions. See also: data item. [IEEE 610.5] IEEE 610-1990
data encoding To apply a code, frequently one consisting of binary numbers, to represent individual or groups of data. Sometimes used as data capture. HDBK-850
Data Extraction Segment (DE/S) Segment of DMA's [NIMA's] Digital Production System which will provide the capability to extract terrain elevation and feature data from stereo soft copy (digital) imagery. Terrain data will be extracted automatically using digital correlation techniques as well as interactively by an operator. Feature data will be extracted interactively utilizing automatic feature recognition techniques. Digital image processing techniques will aid the analyst in the interpretation and extraction of features. See also Digital Production System; MARK 85; MARK 90. HDBK-850
data fusion A formal framework in which are expressed means and tools for the alliance of data originating from different sources, and for the exploitation of their synergy in order to obtain information whose quality cannot be achieved otherwise. DFTC 1997
data fusion (digital mapping) The cartographic registration, or fit, of two or more MC&G data sets. Fusion may occur between different MC&G data forms such as raster and vector, and between data sets of the same data form. The degree of fit required is related to intended use and data set resolution. HDBK-850
data integrity Protection against unauthorized modification, insertion, and deletion. Example: Electronic funds transfer between banks requires protection against modification of the information. [DISA/D2] DISA CFS
data integrity The degree to which a collection of data is complete, consistent, and accurate. [IEEE 610.5] IEEE 610-1990
data integrity 1. The state that exists when computerized data is the same as that in the source documents and has not been exposed to accidental or malicious alteration or destruction. 2. The property that data has not been exposed to accidental or malicious alteration or destruction. JTA 2.0
data interchange The transfer of predefined and structured geographic data from one party to another. CEN/TC 287
data interchange Data exchange (deprecated); procedure for delivery, receipt and interpretation of data. ISO/TC 211
Data Interchange Service {DoD TRM} A service of the Platform entity of the Technical Reference Model that provides specialized support for the interchange of data between applications on the same or different platforms. [TA] DISA CFS
data item A value contained in a data element; for example the data element AGE might contain data items 1, 2, ... Note: The terms data element and data item are often used interchangeably or with the reverse definitions from those given here. No standard of use exists at this time. See also: data element. [IEEE 610.5] IEEE 610-1990
data link An assembly of two or more terminal installations and an interconnecting line. TAFIM 3.0
data link layer Layer two of the OSI Reference Model. It controls the transfer of information between nodes over the physical layer. TAFIM 3.0
Data Management Service {DoD TRM} A service of the Platform entity of the Technical Reference Model that provides support for the management, storage, access, and manipulation of data in a database. TAFIM 3.0
Data Management Working Group Provides imagery community forum to coordinate national imagery-related ADP support. Coordinated by CIO/OTD. USIS 95
data manipulation language A set of operators to enable the query and update of data. CEN/TC 287
data medium The material in or on which data can be recorded and from which data can be retrieved. CEN/TC 287
data model A description of data that consists of all entities represented in a data structure or database and the relationships that exist among them. See also: logical data model; physical data model. [IEEE 610.5] IEEE 610-1990
data model In a database, the user's logical view of the data in contrast to the physically stored data, or storage structure. A description of the organization of data in a manner that reflects the information structure of an enterprise. (DoD 8320.1-M-1, "Data Element Standardization Procedures," January 15, 1993, authorized by DoD Directive 8320.1, September 26, 1991) JTA 2.0
data processing (DP) The systematic performance of operations upon data, such as data manipulation, merging, sorting, and computing. Syn: Information processing. [IEEE 610.2] IEEE 610-1990
data processing system A system, including computer systems and associated personnel, that performs input, processing, storage, output, and control functions to accomplish a sequence of operations on data. [IEEE 610.2] IEEE 610-1990
data quality Refers to the degree of excellence exhibited by the data in relation to its actual portrayal of the actual phenomena. HDBK-850
data quality date A date or range of dates on which a data quality measure is performed on a dataset. NOTE - Data quality date is extensible to time or range of times on which a data quality measure is performed on a dataset if the data producer considers time to be relevant. ISO/TC 211
data quality element A component of the quality of geographic data documenting quantitative information. ISO/TC 211
data quality measure A definition of a specific test performed on a dataset. ISO/TC 211
data quality metrics A result of a described and dated data quality measure consisting of a value or set of values of a defined type. ISO/TC 211
data quality overview element A component of the quality of a dataset documenting non-quantitative information. ISO/TC 211
data quality procedure A description of a specific test performed on a dataset. ISO/TC 211
data quality result A value or set of values resulting from applying a data quality procedure to a dataset. ISO/TC 211
data quality scope A level or reporting group within a dataset on which a data quality measure is performed. NOTE - An entire dataset may be considered as a level. Additionally, if a dataset belongs to a dataset series, level may be extended above a dataset to include the dataset series to which a dataset belongs. ISO/TC 211
data quality subelement One aspect of a data quality element. ISO/TC 211
data quality unit A defined type of a data quality result. ISO/TC 211
data rate 1. The data transfer speed within the computer or between a peripheral and computer. 2. The data transmission speed in a network. (can be expressed in bits per second (b/s)) (Same as Data Transfer Rate). Multimedia
data reduction Process of transforming masses of raw data into useful ordered, or simplified, basic information.. HDBK-850
data repository Physical storage of digital information. NIMA/AR
Data Services Segment (DS/S) Segment of DMA's [NIMA's] Digital Production System which will provide data management and communication services for the MARK 90 phase. It will also provide for data base management and archiving of digital data as well as much of the management data required for operation of the DPS. This segment will have the capability to store one million gigabits of data. It is one of the largest data bases in existence. In addition to its other functions, Data Services will provide an electronic communication network for the DPS. See also Digital Production System; MARK 90. HDBK-850
data set A named collection of related records. Note: Often synonymous with file. [IEEE 610.5] IEEE 610-1990
data smoothing A process which reduces the frequency content of digital data. The information eliminated may be real or artificially introduced from collection processes. The intent is to eliminate and replace inconsistent digital data to provide a more understandable portrayal of the earth's surface. HDBK-850
data spacing The distance between centers of digital data elements in any digital data matrix or evenly spaced array along a given direction. Since the spacing between elements in one direction can be different from that between elements in the other, a complete matrix definition usually requires an expression of both data spacings. HDBK-850
data store A functional grouping of data storage based on the type of information, or use of the storage. A data store in Sybase is a database partition, while in Oracle it is a tablespace. DII COE IRTS
data structure A syntactic structure of symbolic expressions and their storage allocation characteristics. See also chain node; link and node; spaghetti vector; topological entities. HDBK-850
data structure A physical or logical relationship among a collection of data elements. [IEEE 610.5] IEEE 610-1990
data structure A computer interpretable format used for storing, accessing, transferring, and archiving data. ISO/TC 211
data topology Refers to the order or relationship of specific items of data or other items of data. HDBK-850
data transfer To move data from one point to another over a medium. NOTE - Transfer of information implies transfer of data. ISO/TC 211
data transfer modules (DTM) Storage devices, commonly magnetic tape cartridges, used for data exchange or transfer between planning system computers and weapon system computers. HDBK-850
data type A class of data, characterized by the members of the class and the operations that can be applied to them. See also: data structure. [IEEE 610.5] IEEE 610-1990
data warehouse A read only copy of an enterprises data structures. It is utilized to support executive information systems and decision support systems. [DISA/DO3 (CIO)] DISA CFS
database 1. A collection of logically related data stored together in one or more files. Note: Each data item is identified by one or more keys. See also: database management system (DBMS). 2. In CODASYL, the collection of all the record occurrences, set occurrences and areas controlled by a specific schema. [IEEE 610.5] IEEE 610-1990
database management system (DBMS) A computer system involving hardware, software, or both that provides a systematic approach to creating, storing, retrieving and processing information stored in a database. A DBMS acts as an interface between computers' programs and data files as well as between users and the database. It may include backup/recovery, checkpoint processing, and ad-hoc query capability. [IEEE 610.5] IEEE 610-1990
Database Owner {DII COE} The DBMS user account that is the creator or owner of the data objects that are part of the data store segment. DII COE IRTS
database schema The specific data view or design of a particular database. One of the powerful features of a database system is that different applications can have their own view of the database by defining different schema. The database management software handles the details of mapping the actual data representation on disk into the view the application requires. DII COE IRTS
Database Segment {DII COE} A standard method for packaging a physical database for incorporation into the COE/SHADE. Database segments are packaged like any other COE segment. DII COE IRTS
Database Services User {DII COE} A special DBMS user account accessed only by an autonomous application such as a message processor that provides services to other users via the DBMS. DII COE IRTS
Database Session {DII COE} An individual connection between an application program and a database management system. Sessions are defined as a security measure for database accesses. DII COE IRTS
database system A collection of people, machines, and methods organized to accomplish all of the functions of a data base. HDBK-850
Database Utility Service {DoD TRM} A Service of the Support Application Entity of the Technical Reference Model that provides the capability to retrieve, organize, and manipulate data extracted from a database. TAFIM 3.0
dataset 1. A collection of related data. 2. An identifiable collection of data. ISO/TC 211
dataset (UCDM Entity: "DATASET") A set of related data organized for a purpose. USIGS/CDM-A
dataset series A collection of datasets sharing a product specification. ISO/TC 211
date line See international date line. HDBK-850
date time group (DTG) A "time stamp" for a message to include Zulu time, day/month/year (e.g., 121510Z Aug 94 = a message sent on 12 Aug 94 at 1510Z). USIS 95
datum 1. (JCS) Any numerical or geometrical quantity or set of such quantities which may serve as a reference or base for other quantities. Where the concept is geometric, the plural form is "datums" in contrast to the normal plural "data." 2. (geodesy) In geodesy, datum refers to the geodetic or horizontal datum. The classical datum is defined by five elements giving the position of the origin (two elements), the orientation of the network (one element), and the parameters of a reference ellipsoid (two elements). More recent definitions express the position and orientation as functions of the deviations in the meridian and in the prime vertical, the geoid-ellipsoid separation, ana the parameters of a reference ellipsoid. The World Geodetic System (WGS) is a geocentric system that provides a basic reference frame and geometric figure for the earth, models the earth gravimetrically, and provides the means for relating positions on various datums to an earth-centered, earth fixed coordinate system. Also called horizontal datum; horizontal geodetic datum. See also horizontal control datum. 3. (leveling) A level surface to which elevations are referred, usually, mean sea level but may also include mean low water, mean lower low water, or an arbitrary starting elevation(s). Also called vertical datum. See also altitude datum; Cape Canaveral datum; Department of Defense World Geodetic System; European datum; hydrographic datum; Indian datum; international low water; local datum; low water datum; low water springs datum; lower low water datum; Mercury datum; model datum; National Geodetic Vertical datum of 1929; North American datum of 1927; North American datum of 1983; photographic datum; preferred datum; Pulkovo 1932 datum; reference datum; sounding datum; tidal datum; Tokyo datum; vertical control datum; World Geodetic System. HDBK-850
datum An absolute reference system that fixes the origin (earth center) and ellipsoid upon which latitudinal and longitudinal lines are drawn. OGC RFI
datum centered ellipsoid The ellipsoid that gives the best fit to the astrogeodetic network of a particular datum, and hence does not necessarily have its center at the center of the Earth. HDBK-850
datum level (JCS) A surface to which elevations, heights, or depths on a map or chart are related. Also called datum plane; reference level; reference plane. See also altitude. HDBK-850
datum line See reference line. HDBK-850
datum plane See datum level. HDBK-850
datum point (JCS) Any reference point of known or assumed coordinates from which calculations or measurements may be taken. Also called reference point. HDBK-850
datum shifts Three constants which correlate the relationship between the origins of two coordinate reference systems. HDBK-850
datum transformation 1. The systematic determination of differences in origin, orientation and scale between adjoining or overlapping datums or triangulation networks. 2. The act of transforming the coordinates of one datum to another. HDBK-850
day The duration of one rotation of the Earth, or occasionally another celestial body, on its axis. It is measured by successive transits of a reference point on the celestial sphere over the meridian, and each type takes its name from the reference used. See also apparent solar day; astronomic day; calendar day; civil day; constituent day; Julian day; lunar day; mean solar day; modified Julian day; sidereal day; solar day. HDBK-850
DD 1684 DoD Form 1684 message format prescribed by DIA Manual 58-5 for submitting imagery collection/exploitation requirements to DIA. USIS 95
de facto standard A standard that has been informally adopted, often because a particular vendor was first to market with a product that became widely adopted. OpenGIS Guide
de jure standard An official standard created in a "juried" proces [by a recognized standards organization, e.g., ISO] OpenGIS Guide
deadbeat compass See aperiodic compass. HDBK-850
Decca A trade name for a radio phase comparison system which uses master and slave stations to establish a hyperbolic lattice and provide accurate position fixing facilities. HDBK-850
December solstice See winter solstice [(in the northern hemisphere) or summer solstice (in the southern hemisphere)]. HDBK-850
decision view The decision viewpoint documents the decisions about the selection of elements or characteristics. This viewpoint records the rational for architectural choices. IEEE 1471
declination 1. In a system of polar or spherical coordinates, the angle at the origin between a line to a point and the equatorial plane, measured in a plane perpendicular to the equatorial plane. 2. The arc between the Equator and the point measured on a great circle perpendicular to the Equator. 3. (JCS) (astronomy) The angular distance to a body on the celestial sphere measured north or south through 90 from the celestial equator along the hour circle of the body. Comparable to latitude on the terrestrial sphere. 4. Often used as a shortened term for magnetic declination although this use is not preferred. See also grid declination; grid magnetic angle; lunar declination; parallel of declination; solar declination. HDBK-850
declination difference The difference between two declinations, particularly between the declination of a celestial body and the value used as an argument for entering a table. HDBK-850
declination of grid north See grid declination. HDBK-850
declination of the Moon See lunar declination. HDBK-850
declination of the Sun See solar declination. HDBK-850
declinatoire A combined magnetic compass and straight-edge, suitable for use on a planetable to mark the magnetic meridian. Also called box compass; trough compass. HDBK-850
declinometer A magnetic instrument similar to a surveyor's compass, but arranged so that the line of sight can be rotated to conform with the needle or to any desired setting on the horizontal circle. Used in determining the magnetic declination. HDBK-850
decoding The inverse of encoding. ISO/TC 211
decompartmentation The removal of information from a compartmentation system without altering the information to conceal sources, methods, or analytic procedures. USIS 95
decomposition of an object The specification of a given object as a composition. NOTE (not part of the standard) - As an example of the above definitions, an object, A, may be decomposed into a composition of objects, X and Y and Z and, conversely, objects X and Y and Z may be composed into the single object, A RM-ODP
decompress The process by which compressed data is expanded to its former file size. HDBK-850
Defense Acquisition Board (DAB) The DAB is the senior DoD acquisition review board chaired by the USD(A&T). The DAB advises the USD(A&T) on major decisions on individual acquisition programs, specifically, and acquisition policies and procedures, generally. DoDD 5000.1
Defense Advanced Research Projects Agency (DARPA) DARPA is the central research and development organization for the Department of Defense (DoD). It manages and directs selected basic and applied research and development projects for DoD, and pursues research and technology where risk and payoff are both very high and where success may provide dramatic advances for traditional military roles and missions and dual-use applications. DARPA's primary responsibility is to help maintain U.S. technological superiority and guard against unforeseen technological advances by potential adversaries. DARPA is located in Arlington, VA. DARPA Web Site
Defense Airborne Reconnaissance Office (DARO) Formerly the functional manager for all Tactical Intelligence and Related Activities (TIARA)-funded reconnaissance programs. [The Office of the Secretary of Defense (OSD) is undergoing a reorganization in which the functions of the DARO are being transitioned to ASD(C3I) under DASD(C3ISR&SS). DARO is being disbanded by the end of FY98 and its functions are being distributed among several DoD and Military organizations.] USIS 95
Defense Attache System Part of the Defense Intelligence Agency (DIA). Trains, equips and provides direction for the worldwide net of official military representatives. USIS 95
Defense Automated Warning System The core system for processing and disseminating crucial indications and warning data; it is generally implemented at the national and Command level. USIS 95
Defense Courier Service (DCS) Responsible for the physical distribution of classified materials worldwide. USIS 95
Defense Imagery Intelligence Notice The Defense Imagery Intelligence Notice is a two-page self-initiative product providing amplification of a previously disseminated electronic message. The notice deals with a specific issue and uses imagery to convey detailed information accurately. USIS 95
Defense Imagery Reference Series The Defense Imagery Reference Series is encyclopedic intelligence, usually a facility-centered study. It provides detailed imagery analysis that is the foundation of our knowledge about a facility or area and is a vital imagery analysis document. USIS 95
Defense Imagery Reports Defense Imagery Reports are initiative products providing detailed imagery analysis of complete issues that involve developments at one or more targets, order-of-battle changes, or related developments in one or more geographic areas. USIS 95
Defense Information Infrastructure (DII) The DII is the web of communications networks, computers, software, databases, applications, weapon system interfaces, data, security services, and other services that meet the information processing and transport needs of DOD users, across the range of military operations. It encompasses: (1) sustaining base, tactical, DOD-wide information systems, and Command, Control, Communications, Computers, and Intelligence (C4I) interfaces to weapons systems, (2) the physical facilities used to collect, distribute, store, process, and display voice, data, and imagery; (3) the applications and data engineering tools, methods, and processes to build and maintain the software that allow Command and Control (C2), Intelligence, Surveillance, Reconnaissance, and Mission Support users to access and manipulate, organize, and digest proliferating quantities of information; (4) the standards and protocols that facilitate interconnection and interoperation among networks; and (5) the people and assets which provide the integrating design, management and operation of the DII, develop the applications and services, construct the facilities, and train others in DII capabilities and use. DII MP
Defense Information Infrastructure Common Operating Environment (DII COE) The DII COE establishes an integrated software infrastructure which facilitates the migration and implementation of functional mission applications and integrated databases across information systems in the Defense Information Infrastructure. The DII COE provides architecture principles, guidelines, and methodologies that assist in the development of mission application software by capitalizing on a thorough, cohesive set of infrastructure support services. DII MP
Defense Information Network (DIN) A television network based at the Defense Intelligence Analysis Center (DIAC) showing intelligence-related information along with informational data on a daily basis. USIS 95
Defense Information System Network (DISN) A sub-element of the DII, the DISN is the DOD's consolidated worldwide enterprise-level telecommunications infrastructure that provides the end-to-end information transfer network for supporting military operations. It is transparent to its users, facilitates the management of information resources, and is responsive to national security and defense needs under all conditions in the most efficient manner. DII MP
Defense Information Systems Agency (DISA) As the manager for the Defense Information Infrastructure (DII), DISA's mission is to plan, engineer, develop, test, manage programs, acquire, implement, operate, and maintain information systems for C4I and mission support under all conditions of peace and war. DISA is headquartered in Arlington, VA. DISA Web Site
Defense Intelligence Agency (DIA) DIA is a United States Department of Defense (DoD) Combat Support Agency which reports to the Assistant Secretary of Defense for Command, Control, Communications and Intelligence (ASD C3I). DIA's mission is to provide timely, objective and cogent military intelligence to the warfighters - soldiers, sailors, airmen, marines - and to the decisionmakers and policymakers for DoD and the United States Government. DIA serves as the primary intelligence advisor to the Secretary of Defense and other senior officials. Most of DIA's activities are performed at the Defense Intelligence Analysis Center (DIAC) at Bolling AFB in Washington, DC. The Agency's headquarters are located at the Pentagon in Arlington, VA. DIA Web Site
Defense Intelligence Agency Manual A series of documents outlining DIA-wide procedures. USIS 95
Defense Intelligence Analysis Center (DIAC) See Defense Intelligence Agency (DIA). DIA Web Site
Defense Intelligence Electronic Order of Battle The complete worldwide data base of communications. USIS 95
Defense Intelligence Order of Battle System The official recording of all the specific order of battle (OB) in a series of hardcopy and softcopy documents. USIS 95
Defense Intelligence Threat Data System A full-up application suite supporting counterterrorism, counterintelligence and arms proliferation. In addition to data bases, DITDS provides an umbrella of analytic tools that include message handling, network analysis, and Email. USIS 95
Defense Investigative Service (DIS) Now the Defense Security Service (DSS). DSS Web Site
Defense Logistics Agency (DLA) DLA is a ogistics combat support agency whose primary role is to provide supplies and services to America's military forces worldwide. It provides materiel and supplies to the military services and supports their acquisition of weapons and other equipment. DLA provides supply support, contract administration services and technical and logistics services to all branches of the military. DLA is headquartered at Fort Belvoir, VA. DLA Web Site
Defense Message System (DMS) All hardware, software, procedures, standards, facilities, and personnel used to exchange messages electronically between organizations and individuals in DOD. The DMS relies upon DISN. [DISA/D2] DII MP
Defense Meteorological Support Program The collection of weather data, including atmospheric moisture and temperature levels, for U.S. military operations for more than two decades. Military forecasters use the data to detect developing weather patterns around the globe and help identify, locate, and determine the severity of thunderstorms, hurricanes, and typhoons. The systems can also locate and determine the intensity of electromagnetic phenomena that can interfere with radar operations and long-range communications. Systems orbit about 500 miles above the Earth and can scan an area 1,800 miles wide. Each system covers the Earth about every 12 hours. USIS 95
Defense Modeling and Simulation Office (DMSO) DMSO was established to serve as the executive secretariat for the Executive Council on Modeling & Simulation (EXCIMS) and to provide a full-time focal point for information concerning Department of Defense Modeling and Simulation (DoD M&S) activities. Currently the DMSO promulgates M&S policy, initiatives, and guidance to promote cooperation among DoD components to maximize efficiency and effectiveness. DMSO is a staff activity reporting to the DDR&E, office of the USD(A&T). DMSO is located in Alexandria, VA. DMSO Web Site
Defense Readiness Condition (DEFCON) A uniform system of progressive alert postures for use between the Joint Chiefs of Staff and the commanders of U.S. commands and for use by the Services. Defense Readiness Conditions are graduated to match situations of varying military severity (status of alert). Defense Readiness Conditions are identified by the short title DEFCON (5), (4), (3), (2), and (1), as appropriate. (with DEFCON 1 being the highest readiness level and DEFCON 5, the lowest). USIS 95
Defense Reconnaissance Support Program The budgetary program associated with Defense programs. USIS 95
Defense Resources Board (DRB) The DRB is the senior DoD resource allocation board chaired by the Deputy Secretary of Defense. The DRB advises the Deputy Secretary on major resource allocation decisions. DoDD 5000.1
Defense Satellite Communications System (DSCS) The worldwide military satellite network managed by DISA, comprising orbiting space segments and ground terminals that operate in the SHF band to provide long-haul multichannel communications connectivity. [Joint Pub 6-02.1] DISA CFS
Defense Security Service (DSS) As a result of the recent Defense Reform Initiative, the Defense Investigative Service (DIS) has been renamed the Defense Security Service (DSS) to reflect its broader security mission within the Department of Defense. The new DSS includes the DoD Polygraph Institute, the Personnel Security Research Center and the DoD Security Institute. The DSS is an agency of the Department of Defense (DoD)under the direction, authority and control of the Assistant Secretary of Defense for Command, Control, Communications and Intelligence (ASD C3I). DSS was initially established to consolidate DoD personnel security investigations (PSI). DSS is also responsible for the administration of the Defense portion of the National Industrial Security Program, the Arms, Ammunition and Explosives Program, the Key Asset Protection Program, and Counterintellingence support. DSS's mission is to provide to DoD and other Federal agencies an array of security products and services which are designed to deter and detect espionage. DSS is headquartered in Alexandria, VA. DSS Web Site
Defense Sensor Interpretation and Applications Training Program A 3-month course of imagery analysis instruction at Goodfellow AFB, San Angelo, TX. USIS 95
Defense Special Security Communications System (DSSCS) The worldwide message switching network for handling special intelligence (SI) material and eyes only traffic; replaces the former CRITICOMM and SPINTCOMM networks of NSA and DIA. Switching facilities are integrated with AUTODIN and managed by DISA for the DOD intelligence agencies. [Joint Pub 6-02.1] DISA CFS
Defense Special Weapons Agency (DSWA) DSWA served as the Department of Defense's (DoD's) center for nuclear and advanced weapons effects expertise. The Agency's mission was to research and develop technologies to support military systems and satisfy operational requirements. DSWA also managed military nuclear weapons stockpile support and conducts programs associated with Cooperative Threat Reduction (Nunn-Lugar), force protection, arms control technology and counterproliferation support. [Under the auspices of the Defense Reform Initiative, DSWA merged, on October 1, 1998, with the On-Site Inspection Agency (OSIA), the Defense Technology Security Administration (DTSA), and some program functions of the Assistant to the Secretary of Defense for Nuclear, Chemical and Biological Defense Programs to form the Defense Threat Reduction Agency (DTRA).] DSWA Web Site
Defense Support Program (DSP) Detects missile launches, space launches, and nuclear detonations. It feeds warning data to NORAD and USSPACECOM early warning centers at Cheyenne Mountain, CO. It orbits about 22,000 miles above Earth and uses infrared sensors to recognize heat from missile and booster plumes against the Earth's background. USIS 95
Defense Support Program Office The office responsible for DSP located at Peterson AFB, CO. USIS 95
Defense Support Project Office Located in the Pentagon. USIS 95
Defense Switched Network (DSN) A voice and data system. Formerly know as Automatic Voice Network (AUTOVON). USIS 95
Defense Technical Information Center (DTIC) DTIC is a major component of the DoD Scientific and Technical Information Program. DTIC contributes to the management and conduct of Defense research, development, and acquisition efforts by providing access to and transfer of scientific and technical information for DoD personnel, DoD contractors and potential contractors, and other U.S. Government agency personnel and their contractors. DTIC is a part of the Defense Information Systems Agensy (DISA) and is located at Ft. Belvoir, VA. DTIC Web Site
Defense Technology Security Administration (DTSA) The DTSA provided the direction and stewardship for the technology security policies and programs of the U.S. Department of Defense (DoD). DTSA's mission was to develop and implement DoD policies on international transfers of defense-related goods, services, and technologies to ensure such transfers are consistent with national security interests. [Under the auspices of the Defense Reform Initiative, DTSA merged, on October 1, 1998, with the Defense Special Weapons Agency (DSWA), the On-Site Inspection Agency (OSIA), and some program functions of the Assistant to the Secretary of Defense for Nuclear, Chemical and Biological Defense Programs to form the Defense Threat Reduction Agency (DTRA).] DTSA Web Site
Defense Threat Reduction Agency (DTRA) Under the auspices of the Defense Reform Initiative, the On-Site Inspection Agency (OSIA) merged with the Defense Special Weapons Agency (DSWA), the Defense Technology Security Administration (DTSA), and some program functions of the Assistant to the Secretary of Defense for Nuclear, Chemical and Biological Defense Programs. The DTRA, which stood up on October 1, 1998, is the Defense Department's focal point for addressing proliferation of weapons of mass destruction. The mission of DTRA is to reduce the threat to the United States and its allies from nuclear, biological, chemical (NBC), conventional and special weapons through the execution of technology security activities, cooperative threat reduction (CTR) programs, arms control treaty monitoring and on-site inspection, force protection, NBC defense, and counterproliferation (CP); to support the U.S. nuclear deterrent; and to provide technical support on weapons of mass destruction (WMD) matters to the DoD Components. The DTRA is headquartered at Dulles International Airport near Washington, DC [the former headquarters for OSIA]. DTRA Web Site
Defensive Missile Order of Battle A listing of facilities and associated equipment associated with defensive missiles. USIS 95
deferred synchronous request A request where the client does not wait for completion of the request, but does intend to accept results later. Contrast with synchronous request and one-way request. CORBA 2.2
deficiency A functionality needed, but not provided, by the standard. ITSG Vol. 1
definition In imagery interpretation, the degree of clarity and sharpness of an image. HDBK-850
deflecting force See Coriolis force. HDBK-850
deflection angle 1. (surveying) A horizontal angle measured from the prolongation of the preceding line to the following line. Deflection angles to the right are positive; those to the left are negative. 2. (photogrammetry) A vertical angle, measured in the vertical plane containing the flight line by which the datum of any model in a stereotriangulated strip departs from the datum of the preceding model. HDBK-850
deflection angle traverse A survey, usually an open traverse, in which the measurement is made on the deflection angle of each course or leg from the direction of the preceding leg. See also deflection angle, definition 1. HDBK-850
deflection anomaly The difference between an uncorrected value of the deflection of the vertical as determined by observation and the value after being corrected in accordance with certain assumptions made with reference to the physical condition of the geoid. HDBK-850
deflection of the plumb line Deflection of the plumb line has the same value as the deflection of the vertical except the sign of the value is reversed. See also deflection of the vertical. HDBK-850
deflection of the vertical The angular difference, at any place, between the upward direction of a plumb line (the vertical) and the perpendicular (the normal) to the reference spheroid. This difference seldom exceeds 30 seconds except in mountainous terrain or great depths of the sea. Often expressed in two components, meridian and prime vertical. Also called deflection of the plumb line; station error. See also astrogeodetic deflection; gravimetric deflection; topographic deflection. HDBK-850
degaussing range A station for determining magnetic signatures of ships and other marine craft. Such signatures are used to determine required degaussing coil current settings and other required corrective action. HDBK-850
degenerate amphidromic system A system of cotidal lines whose center or nodal (no-tide) point appears to be located on land rather than in the open ocean. HDBK-850
degree of curve The number of degrees of angular measure at the center of a circle subtended by a chord 100 feet in length. In highway surveying, a 100-foot arc is sometimes used instead of a 100-foot chord in defining degree of curve. HDBK-850
degrees of freedom The number of independent equations that may be written from a redundant set of observations in excess of the number of equations required for a unique solution of the unknown parameter. That is, if from a set of redundant observations, n observation equations can be written to associate m number of unknown parameters (n=m), then the independent set of equations (n-m) is known as degrees of freedom in any least squares adjustment of these redundant observations The special, but very common, case of establishing one parameter as the mean of observations establishes u=1 and m-n, i.e., there is only one parameter and it may be uniquely determined by any one of the observations. (In this case, each observation is an equation, e.g., x1=10.2). Therefore, in this special case the degrees of freedom equal (n-1). HDBK-850
de-integration Definition of feature or thematic singles or sets from an integrated data base. HDBK-850
delay (JCS) 1. (radar) The ground distance from a point directly beneath the aircraft to the beginning of the area of radar scan. 2. The electronic delay of the start of the time base used to select a particular segment of the total. HDBK-850
delimiter Symbols such as commas, spaces, or parentheses that mark the boundaries of a specific block of information. [HCI Style Guide] DISA CFS
Demand Driven Direct Digital Dissemination (5D) An imagery-related architecture developed by PACAF to facilitate moving imagery between USPACOM components. 5D has grown to become a capability sponsored by OASD(C3I) DASDI-ST. The objective of 5D is to provide a secondary imagery dissemination and management system for tactical users. 5D is currently operational in PACOM, CENTCOM, EUCOM, TRANSCOM, SOCOM and DIA with over 60 file servers and 3000 plus clients. 5D is expected to be operational until IPA is fielded worldwide. USIS 95
Demonstration and Validation DoD Category 6.3b Advanced technology demonstrations help expedite technology transition from the laboratory to operational use. The demonstrations evaluate integrated technologies in as realistic an operating environment as possible to assess the performance or cost reduction potential of advanced technology. USIS 95
densification network Triangulation stations based on a long-line triangulation scheme but with shorter station-to-station distances established to provide more easily available control of higher accuracy to local users. HDBK-850
densitometer An instrument which is used for measuring light (either transmitted or reflected) in terms of density tolerances. Transmission densitometers measure the full density range of negatives and the reflection densitometer measures the reflection range (density) of opaque copy. A numbered scale or digital display allows accurate readings of specific areas for comparisons or control purposes. HDBK-850
density 1. (photography) A measure of the degree of blackening of an exposed film, plate, or paper after development, or of the direct image (in the case of a printout material). It is defined strictly as the logarithm of the optical opacity, where the opacity is the ratio of the incident to the transmitted (or reflected) light. It varies with the use of scattered or specular light. See also characteristic curve; contrast. 2. (cartography) The amount of detail shown on a map or chart. Density varies with scale and the nature of the area being compiled. 3. (surveying) The number of control points in a given survey or area. HDBK-850
density altitude (JCS) An atmospheric density expressed in terms of the altitude which corresponds with that density in the Standard Atmosphere. HDBK-850
density exposure curve See characteristic curve. HDBK-850
Department of Defense Index of Specifications and Standards (DODISS) A publication that lists federal and military specifications and standards, guide specifications, military handbooks and bulletins, adopted NGSs, and other related standardization documents used by the DOD. [DOD 4120.3-M] DISA CFS
Department of Defense Joint Technical Architecture (DoD JTA) A DoD document designed to provide the minimum set of standards that, when implemented, permit the flow of information in support of the Warfighter. The DoD JTA:
· provides the foundation for interoperability among all tactical, strategic, and combat support services systems;
· mandates the standards and guidelines for system development and acquisition that will significantly reduce cost, development time and fielding time for improved systems, while minimizing the impact on system performance wherever possible;
· communicates to industry DoD's intent to use open systems products and implementations;
· reflects the direction of industry's standards-based product development so that today's emerging technologies can be more readily leveraged by tomorrow's military systems.
JTA 2.0
Department of Defense Manned Space Flight Support Office The DoD Manned Space Flight Support Office coordinates all DoD contingency support to United States manned space flight programs. The United States Space Command (USSPACECOM) is the DoD manager for the Manned Space Flight Support Office. The primary office and staff is located at Patrick AFB, FL. SPACECOM Web Site
Department of Defense World Geodetic System (DoD WGS) A unified world datum based on a combination of all available astrogeodetic, gravimetric, and satellite tracking observations. Previous World Geodetic Systems were WGS 59, WGS 60, WGS 66, and WGS 72. The current system is WGS 84. The system is revised as new geodetic, gravimetric, and satellite data materials change the currently accepted values. HDBK-850
departmental collection Airborne imagery collection missions to satisfy theater/Command requirements. These missions include collection from within recognized air corridors, international airspace, or sovereign airspace. USIS 95
departmental exploitation The imagery exploitation undertaken in support of the assigned mission of a single agency, department, or Command by imagery resources responsive to that authority. USIS 95
Departmental Imagery Collection Program Airborne imagery collection missions tasked to satisfy departmental requirements. They include imagery collection from within recognized air corridors, international airspace, or sovereign airspace. USIS 95
departmental intelligence Intelligence that any department or agency of the Federal Government requires to execute its own mission. USIS 95
Departmental Standardization Office (DepSO) A top level office within each Military Department of Defense Agency responsible for managing the Defense Standardization Program and ensuring that its Lead Standardization Activities and Standardization Management Activities properly implement the policies, procedures, and goals of the Defense Standardization Program. [DOD 4120.3-M] DISA CFS
departure 1. (plane surveying) The orthographic projection of a line on an east-west axis of reference. The departure of a line is the difference of the meridian distances or longitudes of the ends of the line. It is east or positive, and sometimes termed the easting, for a line whose azimuth or bearing is in the northeast or southeast quadrant; it is west or negative, and sometimes termed the westing, for a line whose azimuth or bearing is in the northwest or southwest quadrant. Also called longitude difference. 2. (navigation) The distance between two meridians at any given parallel of latitude, expressed in linear units, usually nautical miles; the distance to the east or west made good by a craft in proceeding from one point to another. HDBK-850
dependency One standard requiring the support of other standards to create a valid implementation. ITSG Vol. 1
dependent resurvey A resurvey for accomplishing a restoration based on the original conditions according to the records. The dependent resurvey is made, first, by identifying existing corners and other recognized and acceptable points of control of the original survey and, second, by restoring the missing corners by proportionate measurements in harmony with the original survey. This type of resurvey is used where there is a fair agreement between the conditions on the ground and the records of the original survey. Titles, areas, and descriptions should remain unchanged. See also independent resurvey. HDBK-850
Deployable Intelligence Data Handling System (DIDHS) A deployable ADP system containing a subset of the intelligence data hosted in the IDHS relevant to the forward area of operations. USIS 95
depressed pole The celestial pole below the horizon. Opposite of elevated pole. HDBK-850
depression angle See angle of depression. HDBK-850
depression contour A closed contour delimiting an area of lower elevation than the surrounding terrain. Directional ticks extend from the contour in a downhill direction. HDBK-850
Deptartment of Defense Intelligence Information System (DoDIIS) DoDIIS is the combination of systems and personnel resident at DIA, the DoD agencies, and Unified Commands supporting intelligence production and operations. DIA IL Site
depth (JCS) The vertical distance from the plane of the hydrographic datum to the bed of the sea, lake, or river. HDBK-850
depth The perpendicular distance of an interior point from the surface of an physical object. ISO/TC 211
depth contour (JCS) A line connecting points of equal depth below the hydrographic datum. Also called bathymetric contour; depth curve; isobath. HDBK-850
depth curve See depth contour. HDBK-850
depth number A numerical value placed upon a depth contour to denote its depth relative to a given datum. Also a depth sounding as it appears on a chart. HDBK-850
depth of field The distance between the points nearest and farthest from the camera which are imaged with acceptable sharpness. HDBK-850
depth of focus The distance that the focal plane can be moved forward or backward from the point of exact focus, and still give an image of acceptable sharpness. Also called focal range. HDBK-850
depth of isostatic compensation The depth below sea level at which the condition of equilibrium known as isostasy is complete. HDBK-850
derived information Incorporating, paraphrasing, restating or generating in new form information that is already classified, and marking the newly developed material consistent with the classification markings that apply to the source information. Derivative classification includes the classification of information based on classification guidance. The duplication or reproduction of existing classified information is not derivative classification. USIS 95
descending node The point at which a planet, planetoid, or comet crosses the ecliptic from north to south, or a satellite crosses the equator of its primary from north to south. Opposite of ascending node. Also called southbound node. HDBK-850
descending pass The portion of a vehicle path around the Earth during which the vehicle is flying south relative to the poles. For a descending pass the sun is on the same side of the Earth as the vehicle and targets will generally be in sunlight. USIS 95
descending vertical angle See angle of depression. HDBK-850
description 1. A term for the formal published data of each triangulation station, bench mark, etc. The data include information of the location and type of mark and enable anyone to go to the immediate locality and identify the mark with certainty. 2. (cadastral surveying) A document listing the metes and bounds of a property. HDBK-850
descriptive name (JCS) Written indication on maps or charts used to specify the nature of a feature (natural or artificial) shown by a general symbol. See also geographic name, place name, and toponym. HDBK-850
descriptor A unique descriptive identifier. EXAMPLE: country name. CEN/TC 287
Descriptor Directory {DII COE} The subdirectory SegDescrip associated with each segment. This subdirectory contains descriptors that provide information required to install the segment. DII COE IRTS
Descriptors {DII COE} Data files (contained in the segment's descriptor directory) that are used to describe a segment to the COE. The software installation and integration process uses descriptor directories and their descriptor files to ensure DII compliance. Descriptor files permit automated integration and installation and are the technique for segments to "self-describe" themselves to the COE. DII COE IRTS
design automation Computer-aided design, concurrent engineering, simulation, and modeling. Includes the computational aspects of fluid dynamics, electromagnetics, advanced structures, structural dynamics, and other automated design processes. USIS 95
Design Concept Review (DCR) A milestone in the development of a system where the review team determines if the requirements imposed are fully understood by the developer and are completely accounted for and determines if the System Design Architecture is reasonable and feasible. The requirements must be allocated to hardware, software, and operations. HDBK-850
Designated Approving Authority (DAA) The official with the authority to formally assume responsibility for operating an AIS or network at an acceptable level of risk. (NSTISSI No. 4009) JTA 2.0
desired mean point of impact Aim point for a bomb string. USIS 95
desktop video conferencing Video communication between users of desktop terminals (or PCs) that involves video and audio of the other party. Multimedia
detail points Selected identified points, especially on oblique photographs, used to assist in correctly positioning features displaced as a result of elevation. HDBK-850
detailing (surveying) The process of tying topographic details to the control net. Objects to be located in a survey may range from single points to meandering streams and complex geological formations. HDBK-850
detect To find or discover the presence or existence of an installation, object, activity, or item of intelligence interest based on its general shape (configuration) and on other contextual information in the scene. USIS 95
detection In imagery interpretation, the discovering of the existence of an object but without recognition of the object. HDBK-850
Deutsche Industrie-Norm (DIN) The German Industrial Standard , DIN is a European system of standardization for mechanical, engineering, and scientific manufactured products. In MC&G, the most notable application is the measurement of film speed. HDBK-850
develop (development) In photography, to subject to the action of chemical agents for the purpose of bringing to view the invisible or latent image produced by the action of light on a sensitized surface; also, to produce or render visible in this way. HDBK-850
developable A surface that can be flattened to form a plane without compressing or stretching any part of it, such as a cone or cylinder. HDBK-850
development environment The software environment required to create, compile, and test software. This includes compilers, editors, linkers, debug software, and developer configuration preferences such as command aliases. The development environment is distinct from the runtime environment, and must be separated from the runtime environment, but it is usually an extension of the runtime environment. DII COE IRTS
deviation (JCS) The angular difference between magnetic and compass headings. Also called magnetic deviation. See also error; residual deviation. HDBK-850
deviation of the vertical Angle at a given point between the plumbline and the direction of the perpendicular to the ellipsoid through the given point. Often resolved into a north and east component. CEN/TC 287
DIA Advanced Imagery Reproduction System A system that provides tailored digital and video images from conventional and digital image systems. USIS 95
diagnostic point A point within a data set with accurate and known geographic location that is used to verify the adequacy or inadequacy of transformation result to the data set. (The diagnostic point is not part of the transformation solution.) HDBK-850
diagonal check Measurements made across the opposite corners of the basic frame of a map projection to insure the accuracy of its construction, or to establish and/or check the scale of reproduction. HDBK-850
diagram on the plane of the celestial equator See time diagram. HDBK-850
diagram on the plane of the celestial meridian A diagram in which the local celestial meridian appears as a circle with the zenith at the top, and the horizon as a horizontal diameter. See also time diagram. HDBK-850
diagram on the plane of the equinoctial See time diagram. HDBK-850
dialog Structured series of interchanges between a user and a computer terminal. Dialogs can be initiated by the computer or the user. Interactive dialog consists of an action by the user followed by a response from the computer or vice versa. [HCI Style Guide] DISA CFS
dialog box Screen display box containing a message requesting additional information from the user. [HCI Style Guide] DISA CFS
dialogue services Communication services based on requests and replies of a client and a server processor in connection with each other through a data network. CEN/TC 287
diameter (magnification) See magnifying power. HDBK-850
diameter enlargement A term used to indicate the degree of enlargement of original copy. A one-diameter enlargement of a 4- by 5-inch original would be 8 by 10 inches. See also times (X) enlargement. HDBK-850
diaphragm stop See relative aperature. HDBK-850
diapositive (JCS) (photogrammetry) A positive photograph on a transparent medium. The term is generally used to refer to a transparent positive on a glass plate used in a plotting instrument, a projector, or a comparator. HDBK-850
diapositive printer A photographic device for producing diapositives from aerial negatives. Also called reduction printer. See also fixed-ratio projection printer. HDBK-850
difference of elevation The vertical distance between two points, or the vertical distance between the level surfaces that pass through the two points. HDBK-850
difference of latitude 1. The shorter arc of any meridian between the parallels of two places, expressed in angular measure. 2. (plane surveying) The difference of latitude of the two ends of a line is frequently called latitude of the line, and defined as the orthographic projection of the line on a reference meridian. The latitude (as above defined) of the middle of a line is also referred to as latitude of the line. HDBK-850
difference of longitude The smaller angle at the pole or the shorter arc of a parallel between the meridians of two places, expressed in angular measure. HDBK-850
differential aberration The difference between the aberration of stars and that of a moving object (e.g., a satellite). Also called parallactic aberration. HDBK-850
differential distortion The resultant dimensional changes in length and width in any medium. See also differential shrinkage. HDBK-850
Differential Global Positioning System A positioning procedure that uses two receivers, a rover at an unknown location and a base station at a known, fixed location. The base station computes corrections based on the differences between its actual and observed ranges to the satellites being tracked. USIS 95
differential leveling The process of measuring the difference of elevation between any two points by spirit leveling. See also direct leveling. HDBK-850
differential shrinkage The difference in unit contraction along the grain structure of the material as compared to the unit contraction across the grain structure; frequently refers to photographic film and papers and to map materials in general. HDBK-850
differential temperature A natural error in surveying whereby temperature variations in the instrument cause reading errors that cannot be detected. It is usually caused by direct sunlight on the instrument which can be minimized by shading the instrument during survey operations. HDBK-850
diffraction (optics) The bending of light rays around the edges of opaque objects. Due to diffraction, a point of light seen or projected through a circular aperture will always be imaged as a bright center surrounded by light rings of gradually diminishing intensity. Such a pattern is called a diffraction disk, airy disk, or centric. HDBK-850
diffuse reflection Any reflection process in which the reflected radiation is sent out in many directions usually bearing no simple relationship to the angle of incidence. See also diffusion; specular reflection. HDBK-850
diffusion The scattering of light rays either when reflected from a rough surface or during the transmission of light through a translucent medium. HDBK-850
digital Pertaining to quantities in the form of discrete, integral values. Contrast with: analog. [IEEE 610.1] IEEE 610-1990
Digital Aeronautical Flight Information File (DAFIF) A flight information data base containing airports, heliports, navigational aids, airspace, enroute and terminal data covering both the high and low enroute structures worldwide. The DAFIF incorporates U.S. Military selected aeronautical data similar to the data appearing in the Flight Information Publications (FLIP) suite of products. The data contained herein may not be applicable to other users. HDBK-850
Digital Bathymetric Data Base (DBDB) A gridded bathymetric data base portraying depths in uncorrected meters for each 5 minutes of latitude and longitude. Available on magnetic tape. HDBK-850
Digital Chart of the World (DCW) DCW is the first NIMA product employing the Vector Product Standard (VPS). It provides global coverage of the earth's land surface at a 1:1,000,000 scale information content which includes all the information found on the base map for the Operational Navigational Chart Series. Application software is provided to allow data base queries by feature/attribute or spatial selection. Data output is to hard disk, text file, or plot file. See also Vector Product Format (VPF). HDBK-850
Digital Chart of the World (DCW) Project A NIMA R&D project designed to develop, refine, and establish a suite of standards to support future Defense Mapping Agency digital data products and enhance the utility of digital information in vector format. See also Vector Product Format. HDBK-850
Digital Cities Data Base (DCDB) A DMA [NIMA] standard product consisting of the outlines of cities digitized from Operational Navigation Charts (ONC). HDBK-850
digital data These are data represented in alphanumeric format readable by a computer. HDBK-850
digital data base (off-line) A digital data base maintained in a common format that supports different user systems, e.g., simulator or weapon systems. Normally the data must be transferred before it can be used by a specific user system. This term is commonly expressed as the off-line data base. HDBK-850
digital data base (on-line) A digital data base in the format needed by a user system, e.g., simulator or weapon system, and which can be loaded into the user system. This term is commonly referred to as the on-line data base. HDBK-850
digital elevation model (DEM) A representation of the bare surface of the earth with natural and man-made structures and features removed that is described by a regular or irregular grid of discrete terrain elevation values, usually referenced to the geoid (i.e., Mean Sea Level). See also Digital Terrain Elevation Data (DTED); digital terrain model (DTM). OGC RFI
Digital Feature Analysis Data (DFAD) (A&D LDM Entity: "DIGITAL-FEATURE-ANALYSIS-DATA") A description and portrayal of planimetric features in NIMA standard digital format. A&D LDM
Digital Feature Analysis Data (DFAD) A data base consisting of selected natural and cultural planimetric features, type classified as point, line, or area features as a function of their composition and size. Each feature is assigned a code and further described with limited attribution. The data are stored in polygon format and segregated into 1 degree tiles. Primary applications are radar return, simulation, navigation, targeting and terrain obstruction studies. When combined with DTED, an off-line data base is created for use by simulators needing line-of-sight, obstruction, and perspective views. DFAD may also be used for sensor correlation, target recognition, lines of communication analysis, or for map production activities. HDBK-850
digital feature data 1. (cultural data) Man-made, natural and landscape features in digital form, data in discrete digital (numerical) form, including all man-made features on the Earth's surface, e.g., lines of communication, built-up areas (cities), transmission lines and landmark structures. 2. (hydrographic data) Data derived from the measurement and description of physical features of the oceans, lakes, rivers and other waters, and their adjoining coastal areas (with particular reference to navigational usage) in digital form. 3. (landscape feature data) Data of all natural features and man's alteration to those features, e.g., lake with dam, agricultural features, etc., in digital form. 4. (natural feature data) Natural features on the Earth's surface which are not man-made, e.g. vegetation, water bodies, desert, etc. in digital form. HDBK-850
digital feature height model A height model of natural and man-made features above the bare surface of the earth. This model can be derived from stereo pairs of air photos or satellite imagery stereo pairs. OGC RFI
Digital Flight Information Publication (DFLIP™) DFLIP™ is a vector-based digital database containing selected aeronautical features. DFLIP™ data is derived from multiple sources, including DAFIF (Digital Aeronautical Flight Information File) data and airport specific data extracted from airport diagrams, FLIP charts, and Time Zone charts. DFLIP™ is a general purpose global database designed to support aeronautical navigation and geographic information system (GIS) applications. DFLIP™ will be produced world-wide. NIMA Web Site
Digital Geographic Information (DGI) The digital representation of elevation and sounding information, geographic feature geometry and feature attribute information, information concerning the appearance and status of the earth's surface and its features in the electromagnetic spectrum (e.g., radar, infrared, etc.), Military Geographic Information together with other ancillary information, and other digital information. HDBK-850
Digital Geographic Information Exchange Standard (DIGEST) A set of standards developed by the North Atlantic Treaty Organization's (NATO) Digital Geographic Information Working Group (DGIWG) designed to support the exchange of digital geographic data between co-producers. These standards apply to geodetic, geographic, geological, and geophysical data of military interest, as well as positioning, navigation, simulation, target recognition, map and chart automated production, and data display and manipulation applications. DIGEST Web Site
Digital Geographic Information Working Group (DGIWG) The DGIWG is a the multinational body responsible to member nations for coordinated, advice and policy recommendations on Digital Geographic Information Systems, including the technical mechanisms required to achieve co-production, of concern to member nations and to the North Atlantic Treaty Organization (NATO). There are currently 13 participating member nations. They are: Belgium, Canada, Denmark, France, Germany, The Netherlands, Norway, Spain, United Kingdom, Italy and United States. Australia , Greece, Portugal and New Zealand are associate member nations. DIGEST Web Site
digital image An image that has been converted to an array of pixels, each of which has an associated value called its gray level. Note: A digital image may be referred to as an image when the intended meaning is clear from the context. Syn: digitized image. [IEEE 610.4] IEEE 610-1990
Digital Image Data Output Product Image data recorded digitally on magnetic media. USIS 95
digital imagery data requirements Data defining the quantities of digital imagery and the required timelines for physical delivery; the distribution criteria for each imagery recipient; and the definition of image electronic dissemination codes. USIS 95
Digital Imagery Exploitation and Production System (DIEPS) A desktop imagery processing workstation capable of enhancing and annotating imagery. Used by United States Southern Command (USSOUTHCOM). USIS 95
Digital Imagery Processing System (DIPS) Performs imagery enhancement and precision mensuration of softcopy imagery received via Digital Image Data Output Product (DIDOPs) and softcopy imagery digitized from hardcopy products. USIS 95
Digital Imagery Workstation (DIWS) Performs the digital product creation segment of the Theater Mission Planning Center Upgrade (TMPC-U) within the Cruise Missile Support Activity (CMSA). USIS 95
Digital Landmass Blanking System (DLMB) A land/water matrix of elevation values, where a value of 200 meters is arbitrarily assigned to land and a value of 0 meters is assigned over water. These matrix data are used by the E-3A Airborne Warning and Control Systems (AWACS), operating in a maritime/coastal environment to filter out unwanted radar returns from land and allow for better detection of ship and aircraft movement near the shoreline. HDBK-850
Digital Landmass System (DLMS) An off-line cartographic data base consisting of two basic types of digital data files, one containing Terrain Elevation Data and the other containing cultural and natural feature data, maintained by NIMA to support various user systems e.g., simulators and weapon systems. Formerly known as Digital Radar Landmass Simulator (DRLMS). See also Digital Feature Analysis Data (DFAD); Digital Terrain Elevation Data (DTED). HDBK-850
digital line graph (DLG) A form of digital map developed by the United States Geological Survey (USGS). DLGs supply users with the digital version of information printed on USGS topographical quadrangle maps. OpenGIS Guide
digital line graph-enhanced (DLG-E) An extension of the DLG topological model which builds a cartographic feature layer upon the topology. Nonlocational characteristics of feature objects are linked with the spatial or locational objects. See also digital line graph (DLG). HDBK-850
digital map 1. A map expressed and stored in digital form. 2. A representation in digital form, discrete points on the Earth's surface. Also called numerical map. HDBK-850
Digital Nautical Chart (DNC™) DNC™ is a vector-based digital database containing selected maritime significant physical features collected from Harbor, Approach, Coastal, and General charts in a format suitable for computerized marine navigation and geographic information system (GIS) applications. DNCY will be produced world-wide. The DNC™ is based on the feature content of the hardcopy Harbor (HAC 1), Approach (HAC 2), Coastal (HAC 3) and General (HAC 6) charts produced by NIMA. NIMA Web Site
digital orthoimage An aerial photograph or satellite image that has been computer corrected to remove geometric distortions caused by the imaging sensor and terrain relief displacement. An example would be a digital image map without perspective. OGC RFI
digital orthophoto A digital image that has the properties of an orthographic projection. It is derived from a digitized perspective aerial photograph or other remotely sensed image data by differential rectification so that image displacements caused by camera tilt and terrain relief are removed. USGS Web Site
digital orthophoto quadrangle (DOQ) See digital orthophoto. USGS Web Site
Digital Point Positioning Data Base (DPPDB) A deployable set of geographically controlled imagery with associated support data. DPPDBs are developed by the National Imagery and Mapping Agency (NIMA) over user-specified areas to provide a capability for deriving accurate positional data on a quick-response basis for any identifiable feature within a DPPDB area. This includes geodetic latitude, geodetic longitude, geodetic elevation, and associated accuracies of desired points. Targets, navigational points, and launch sites are examples of such points of interest. The DPPDB is a "data only" product and the exploitation of the data will be defined by each user's hardware and software capabilities. NIMA LOP
Digital Point Positioning Data Base (DPPDB) Exploitation Workstation Drop Software (DEW_Drop) See DPPDB Exploitation Workstation Drop Software (DEW_Drop). NIMA Web Site
Digital Production System (DPS) NIMA's production system for accurate and timely digital or softcopy products and services. DPS includes hardware and software developments as well as an MC&G digital data base which supports the generation of multiple products over any geographic area. The first phase, MARK 85, was to achieve maximum effective enhancement of existing NIMA production capabilities. The MARK 90 phase integrates portions of MARK 85 with additional hardware and software for digital or soft copy operations. See also Data Integration Segment; Source Acquisition Segment; Hardcopy Exploitation Segment; Universal Rectifier Segment; Production Management Segment; Data Services Segment; Source Preparation Segment; Data Extraction Segment; Product Generation Segment; MARK 85; MARK 90. HDBK-850
digital raster graphic (DRG) A DRG is a scanned image of a topographic map. The scanned image includes all map collar information. The image inside the map neatline is georeferenced to the surface of the Earth. The DRG can be used to collect, review, and revise other digital data, especially a digital line graph (DLG). When the DRG is combined with other digital products, such as a digital orthophoto quadrangle (DOQ) or a digital elevation model (DEM), the resulting image provides additional visual detail for the extraction and revision of base cartographic information. USGS Web Site
Digital Subscriber Voice Terminal One of the six TRI-TAC terminals. A telephone instrument with encryption device (KY-68) to digitize voice for secure voice traffic. USIS 95
digital synthesized data Data derived from the analysis of two or more different types of data such as Digital Terrain Elevation Data, Digital Natural Feature Data, and Digital Cultural Feature Data. An example is the derivation of data which can assess the effects of soil types, vegetation slope, drainage and microrelief on cross-country movement of vehicles. HDBK-850
digital synthetic data Data in numerical format that describes either totally or partially fictitious information generated from lower resolution/frequency input. HDBK-850
digital tape recorder system incremental A recorder used to record and store large amounts of data. USIS 95
Digital Terrain Analysis Data (DTAD) Data in discrete digital (numerical) form representing natural and manmade features. Feature data are attributed and typically grouped in files for transportation, vegetation, surface configuration, surface materials, surface drainage, and abstacle analysis. The various data base products comprised of DTAD are used in terrain analysis, targeting, battlefield modeling and simulation. HDBK-850
Digital Terrain Elevation Data (DTED) (A&D LDM Entity: "DIGITAL-TERRAIN-ELEVATION-DATA") A geographic matrix of terrain elevation data points converted into a numerical format for computer storage and analysis at precise increments of latitude and longitude. A&D LDM
Digital Terrain Elevation Data (DTED) A uniform matrix of terrain elevation values. DTED provides basic quantitative data for all military training, planning, and operating systems requiring terrain elevation, slope, and/or surface roughness information. Level 2 post spacing is 1 arc second latitudinally. Level 1 post spacing is 3 arc second latitudinally; for both, longitudinal spacing varies with latitude. HDBK-850
digital terrain matrix (DTM) A regular grid of geographic or model coordinates that is the primary output of the collection process. The data contained therein consists of elevation data referred to a grid (row and column occurrences) system. Grid spacing may vary according to surface model accuracy requirements. HDBK-850
digital terrain model (DTM) A statistical representation of the continuous surface of the ground by a large number of selected points with known rectangular coordinates in an arbitrary coordinate field. See also digital elevation model (DEM). HDBK-850
digital terrain model (DTM) Any representation of the bare surface of the earth with natural and man-made features removed. The representation may be in the form of elevation posts, surface polynomials, irregular patches (e.g., TIN) or contours. OGC RFI
digital terrain model (DTM) A method of transforming elevation data into a contoured surface of a three-dimensional display. OpenGIS Guide
digitization The process of converting hardcopy maps/photographs, or video (analog) data into a digital form. USIS 95
digitize The process of converting information into the digital codes stored and processed by computers. In geographic applications, digitizing ususlly means tracing map features into a computer using a digitizing tablet, graphics tablet, mouse, or keyboard cursor. OpenGIS Guide
digitized raster graphics (DRG) The data are composed of digitized large-scale and small-scale map coverage. DRG data are transferred and stored in blocks structured similar to and sized the same as image fast access format (FAF) blocks. USIS 95
dihedral angle The angle between two intersecting planes. HDBK-850
dimensional stability 1. Ability to maintain size. 2. Resistance to dimensional changes caused by changes in moisture content and temperature. HDBK-850
diopter A unit of measurement of the power of a lens, especially a spectacle type lens. The power in diopters equals the reciprocal of the focal length in meters; thus, a lens whose focal length is 20 cm has a power of 5 diopters. HDBK-850
dioptric system (optics) An optical system containing only refractive elements (lenses). HDBK-850
dip 1. The vertical angle, at the eye of an observer, between the horizontal and the line of sight to the visible horizon. Also called dip of the horizon. 2. The angle between the horizontal and the lines of force of the Earth's magnetic field at any point. Also called inclination; magnetic dip; magnetic inclination; magnetic latitude. 3. The first detectable decrease in the altitude of a celestial body after reaching its maximum altitude on or near meridian transit. HDBK-850
dip angle 1. (surveying) The vertical angle of the observation point between the plane of the true horizon and a sight line to the apparent horizon. 2. (photogrammetry) The vertical angle, at the air station, between the true and the apparent horizon, which is due to flight height, Earth curvature, and refraction. HDBK-850
dip circle An instrument for measuring magnetic dip. It consists essentially of a dip needle, or magnetic needle, suspended in such a manner as to be free to rotate about a horizontal axis. HDBK-850
dip correction See height-of-eye correction. HDBK-850
dip equator See magnetic equator. HDBK-850
dip needle See magnetic dip needle, definition 1. HDBK-850
dip of the horizon See dip, definition 1. HDBK-850
dip pole See magnetic pole. HDBK-850
Direct Air Support Center A critical node of the Marine Corps tactical air command and control system; its function is to oversee the execution of air support for the Ground Combat element (GCE) of a MAGTF. Also serves as clearinghouse for Ground Combat Element (GCE) and Air Combat Element (ACE) intelligence data. USIS 95
direct angle An angle measured directly between two lines, as distinguished in transit traverse from a deflection angle. HDBK-850
direct down link The ability for a sensor to communicate directly (line of sight) to its ground station. USIS 95
direct evaluation method A method of evaluation quality of geospatial data set based on data quality metric values estimated by sampling or by automated inspection. ISO/TC 211
direct leveling The determination of differences of elevation by means of a continuous series of short horizontal lines. Vertical distances from these lines to adjacent ground marks are determined by direct observations on graduated rods with a leveling instrument equipped with a spirit level. See also differential leveling. HDBK-850
direct measurement Any measurement obtained by applying a tape to a line or a protractor to an angle, or by turning an angle with a transit; especially applicable to surveying. See also indirect measurement. HDBK-850
direct motion The apparent motion of a planet or other object eastward among the stars. HDBK-850
direct observation A measure of the quantity whose value is desired, such as a single measure of a horizontal angle. HDBK-850
direct photography Photography in which the image of a subject is recorded directly by the camera in the conventional manner. HDBK-850
direct positive A positive image obtained directly without the use of a negative. HDBK-850
direct problem The determination of the geodetic position of the end point and the back azimuth at position two when the given information is the latitude and longitude of position one, along with the forward azimuth and the distance between the two points. HDBK-850
direct radial plot See direct radial triangulation. HDBK-850
direct radial triangulation A graphic radial triangulation made by tracing the directions from successive radial centers directly onto a transparent plotting sheet rather than laying the triangulation by the templet method. Also called direct radial plot. HDBK-850
direct scanning camera A type of panoramic camera wherein the lenses swing or rotate about the rear nodal point at a given rate. HDBK-850
direct spatial reference system A spatial reference system based upon a co-ordinate system. CEN/TC 287
Direct Support Imagery Interpretation Report A third-phase textual and graphic hardcopy presentation used to disseminate comprehensive and detailed photo intelligence information. USIS 95
direct telescope A telescope is said to be direct when it is in its normal position. HDBK-850
direct vernier A vernier scale which has spaces or divisions slightly shorter than those of the primary scale. The numbers on the vernier scale coincide with the numbers on the primary scale. HDBK-850
directed energy An umbrella term covering technologies that relate to the production of a beam of concentrated electromagnetic energy or atomic or subatomic particles. USIS 95
directed search area An area defined by a polygon that has from three to 24 vertices. USIS 95
directed-energy device A system using directed energy primarily for a purpose other than as a weapon. Directed-energy devices may produce effects that could allow the device to be used as a weapon against certain threats; for example, laser rangefinders and designators used against sensors that are sensitive to light. See also directed-energy; directed-energy weapon. USIS 95
directed-energy warfare Military action involving the use of directed-energy weapons, devices, and countermeasures to either cause direct damage or destruction of enemy equipment, facilities, and personnel, or to determine, exploit, reduce, or prevent hostile use of the electromagnetic spectrum through damage, destruction, and disruption. It also includes actions taken to protect friendly equipment, facilities, and personnel and retain friendly use of the electromagnetic spectrum. USIS 95
directed-energy weapon A system using directed energy primarily as a direct means to damage or destroy enemy equipment, facilities, and personnel. USIS 95
direction 1. (JCS) A term used by a spotter or observer in a call for fire to indicate the bearing of the spotting line. 2. The position of one point relative to another without reference to the distance between them. Direction may be either two-dimensional or three-dimensional, the horizontal being the usual plane of the latter. Direction is usually indicated in terms of its angular distance from a reference direction. See also great-circle direction; grid direction; horizontal direction; magnetic direction; Mercator direction; reference direction; relative direction; true direction; x-direction. HDBK-850
direction angle In tracking, the angle between the antenna base line and an imaginary line connecting the center of the base line with the target . HDBK-850
direction instrument theodolite A theodolite in which the graduated horizontal circle remains fixed during a series of observations, the telescope being pointed on a number of signals or objects in succession, and the direction of each read on the circle, usually by means of micrometer microscopes. Direction instrument theodolites are used almost exclusively in first- and second-order triangulation. Also called direction theodolite; triangulation theodolite. HDBK-850
direction method of adjustment (triangulation and traverse) A method of adjustment of observations which determines corrections to observed directions. The direction method is used in the adjustment of first- and second-order survey observations. HDBK-850
direction method of determining astronomic azimuth The determination of the astronomic azimuth of a line by measuring, with a direction theodolite, the horizontal angle between a selected star and a suitable mark, and applying that angle to the azimuth of the star computed for the epoch of the observation. HDBK-850
direction method of measuring horizontal angles See direction method of observation. HDBK-850
direction method of observation A method of observing angular relationships wherein the graduated circle is held in a fixed position, and the directions of the various signals are observed around the horizon. Thus, directions are pointings whereby angles are found by the differences in directions. Also called direction method of measuring horizontal angles. HDBK-850
direction of gravity See direction of the force of gravity. HDBK-850
direction of relative movement The direction of motion relative to a reference point, itself usually in motion. HDBK-850
direction of the force of gravity The direction indicated by a plumb line. It is perpendicular to the surface of the geoid. Also called direction of gravity. HDBK-850
direction of tilt The direction (azimuth) of the principal plane of a photograph. Also, the direction of the principal line on a photograph. HDBK-850
direction theodolite See direction instrument theodolite. HDBK-850
directional radar prediction (JCS) A prediction made for a particular heading. HDBK-850
directional reflectance Reflectance measured for a specific mode of irradiation and collection. HDBK-850
Director of Intelligence, Marine Corps The senior USMC intelligence-related leadership position. USIS 95
Director of Naval Intelligence Senior leadership position for Naval Intelligence. USIS 95
Director, Central Intelligence (DCI) The President's principal foreign intelligence adviser appointed by him with the consent of the Senate to be head of the Intelligence Community and Director of the CIA. USIS 95
Director, Central Intelligence Directive (DCID) A directive issued by the Director, Central Intelligence that outlines general policies and procedures to be followed by intelligence agencies and organizations that are under his direction or overview. USIS 95
Director, National Security Agency The senior leadership position for the agency with offices at Fort Meade, MD. USIS 95
directory A collection of open systems cooperating to provide directory services. [DISA/D2] DISA CFS
Directory Service {DoD TRM} A service of the External Environment entity of the Technical Reference Model that provides locator services that are restricted to finding the location of a service, location of data, or translation of a common name into a network specific address. It is analogous to telephone books and supports distributed directory implementations. TAFIM 3.0
Directory System Agent (DSA) An Open Systems Interconnection (OSI) application process that is part of the directory and whose role is to provide Directory User Agents access to the directory information base (DIB). A DSA may use information stored in its local database or interact with other DSAs to carry out request. Alternatively, the DSA may direct a requestor to another DSA that can help carry out the request. [DISA/D2] DISA CFS
Directory User Agent (DUA) An Open Systems Interconnect (OSI) application process that represents a user in accessing the directory. Each DUA serves a single user so that the directory can control access to directory information on the basis of the DUA names. DUAs can also provide a range of utilities to assist users in composing requests (queries) and interpreting responses. [DISA/D2] DISA CFS
direct-support exploitation Imagery exploitation that supports the assigned mission of a single agency, department, or command. USIS 95
disclosure The oral transmittal of information to an individual or individuals, or the visual exposure of tangible products such as images or textual or graphic materials. During "disclosures," imagery and other disclosed products remain in U.S. custody and control at all times. USIS 95
discrepancy A difference between results of duplicate or comparable measures of a quantity. The difference in computed values of a quantity obtained by different processes using data from the same survey. HDBK-850
discrepancy report A means to identify problems, defects, errors in a system under configuration management. USIS 95
dispersion (optics) The separation of light into its component colors by its passage through a diffraction grating or by refraction such as that provided by a prism. HDBK-850
displacement 1. (cartography) The horizontal shift of the plotted position of a topographic feature from its true position, caused by required adherence to prescribed line weights and symbol sizes. 2. Any shift in the position of an image on a photograph which does not alter the perspective characteristics of the photograph (i.e., shift due to tilt of the photograph, scale change in the photograph, and relief of the objects photographed). See also refraction displacement; relief displacement; tilt displacement; x-displacement; y-displacement. HDBK-850
display The graphic presentation of the output data of any device on system. HDBK-850
dissemination Conveyance of intelligence to users in a suitable form. JPUB 2-0
dissemination The electronic transmission of imagery or imagery derived information in a digital or analog form. USIS 2-1.1
dissolve (digital) The process of removing shared common attributes by eliminating the shared boundaries when merging two or more polygons. HDBK-850
distance The spatial separation of two points, measured by the length of a line joining them. See also angular distance; double meridian distance; double zenith distance; ecliptic polar distance; electrical distance; external distance; falling; front focal distance; great-circle distance; grid length; ground distance; hyperfocal distance; interocular distance; lunar distance; meridian distance; meridional distance; plus distance; polar distance; principal distance; projection distance; relative distance; rhumb line distance; slant range; Sun-zenith distance; tangent distance; time distance; zenith distance. HDBK-850
distance angle An angle in a triangle opposite a side used as a base in the solution of the triangle, or a side whose length is to be computed. HDBK-850
distance learning Learning situations in which the information and the learner(s) are geographically separated. Multimedia
distance measuring equipment (DME) See electronic distance measuring equipment. HDBK-850
distance prorate rule A method of balancing a survey. A rule for holding angles to their recorded values and prorating the lengths of the lines in the traverse; operated by locating the bearings to a convenient meridian, preferably the closing line of the traverse, and prorating the dimensions through a trigonometric process. HDBK-850
distant points Similar to tie points but which appear only on the obliques facing outward on the perimeter of a compilation. Distant points unite the sets of a strip into a flight unit; but, unlike tie points, do not serve to join several flight strips together. HDBK-850
distortion Lens aberrations affecting the positions of images from their true relative positions. See also aberration, definition 2; angular distortion, definition 2; differential distortion; film distortion; image distortion; image motion compensation distortion; lens distortion; linear distortion; panoramic distortion; radial distortion; scan positional distortion; tangential distortion; tipped panoramic distortion. HDBK-850
distortion compensation (photogrammetry) In a double projection direct viewing plotter system, that correction applied to offset the effect of radial distortion introduced in an original negative by the objective lens of an aerial camera. HDBK-850
distortion curve A curve representing the linear distortion characteristics of a lens; it is plotted with image radial distance from the lens axis as abscissas and image radial displacements as ordinates. HDBK-850
distributed (system, processing) A system or process consisting of interdependent software or hardware/software entities separated either physically or chronologically. ITSG Vol. 1
distributed computing Same as distributed processing. Freedman 1995
distributed computing A type of computing in which different components and objects comprising an application can be located on different computers connected to a network. So, for example, a word processing application might consist of an editor component on one computer, a spell-checker object on a second computer, and a thesaurus on a third computer. In some distributed computing systems, each of the three computers could even be running a different operating system. Distributed computing is a natural outgrowth of object-oriented programming. Once programmers began creating objects that could be combined to form applications, it was a natural extension to develop systems that allowed these objects to by physically located on different computers. One of the requirements of distributed computing is a set of standards that specify how objects communicate with one another. There are currently two chief distributed computing standards: CORBA and DCOM. PC Webopaedia
Distributed Computing Environment (DCE) DCP [Distributed Computing Platform] being developed by the Open Software Foundation (OSF) [now called The Open Group]. OpenGIS Guide
Distributed Computing Platform (DCP) A collection of software components that support interoperability and transparency across multiple heterogeneous networked computers in various network configurations. OpenGIS Guide
distributed data processing The use of computers for processing information within a distributed system. [IEEE 610.2] IEEE 610-1990
distributed database 1. A database that is not stored in a central location but is dispersed over a network of interconnected computers. 2. A database under the overall control of a central database management system but whose storage devices are not all attached to the same processor. 3. A database that is physically located in two or more distinct locations. [FIPS PUB 11-3] DISA CFS
Distributed Interactive Simulation (DIS) 1. Program to electronically link organizations operating in the four domains: advanced concepts and requirements; military operations; research, development, and acquisition; and training. 2. A synthetic environment within which humans may interact through simulation(s) at multiple sites networked using compliant architecture, modeling, protocols, standards, and data bases. (DoD 5000.59-P, "Modeling and Simulation Master Plan," October 1995, authorized by DoD Directive 5000.59, January 4, 1994) JTA 2.0
distributed processing Also called distributed computing, it is a system of computers connected by a communications network. The term is used loosely to refer to any computers with communications between them. However, in true distributed processing, each computer system is sized to handle its local workload, and the network has been designed to support the system as a whole. Freedman 1995
distributed processing Information processing in which discrete components may be located in different places, and where communication between components may suffer delay or may fail. RM-ODP
Distributed Production Program Formerly referred to as the Delegated Production Program. This is DIA's program for U.S. Commands producing specific reporting on specific subjects. USIS 95
distributed system A computer system in which several interconnected computers share the computing tasks assigned to the system. [IEEE 610.2] IEEE 610-1990
distribution map A map which shows the geographic arrangement of a specific product, commodity, or formation. HDBK-850
distribution transparency Abstraction of the complexity of distribution processing from particular system users (such as application software developers). The standard distribution transparencies include: access, failure, location, migration, relocation, replication, persistence, and transaction. RM-ODP
disturbing function See disturbing potential, definition 2. HDBK-850
disturbing potential 1. (geodesy) The difference between the gravity potential of the actual Earth and the potential function of the normal gravity. Also called potential disturbance; potential of disturbing masses; potential of random masses. 2. (astronomy) The difference between the total gravitational potential and the potential pertaining to a spherical mass distribution. Also called disturbing function. HDBK-850
diurnal Having a period of, occurring in, or related to a day. HDBK-850
diurnal aberration Aberration resulting from the rotation of the Earth on its axis. The value of diurnal aberration varies with the latitude of the observer and ranges from zero at the poles to 0.32 second of arc at the Equator. A correction for diurnal aberration is applied to astronomic observations for longitude and azimuth. Also called daily aberration. HDBK-850
diurnal age See age of diurnal inequality. HDBK-850
diurnal arc See astronomic arc. HDBK-850
diurnal circle The apparent daily path of a celestial body, approximating a parallel of declination. HDBK-850
diurnal constituent Any tide constituent whose period approximates that of a lunar day (24.84 solar hours). See also constituent. HDBK-850
diurnal inequality The difference in heights and durations of the two successive high waters or of the two successive low waters of each day; also, the difference in speed and direction of the two flood currents or the two ebb currents of each day. Also called daily inequality; low water inequality. HDBK-850
diurnal motion The apparent daily motion of a celestial body. HDBK-850
diurnal parallax See geocentric parallax. HDBK-850
diurnal variation That component of a determinable magnitude which passes through a complete cycle in one day. HDBK-850
divergence (leveling) The difference between the numerical values of two runnings over the same section of a line of levels. HDBK-850
diverging lens See negative lens. HDBK-850
diversity The ability of a system or components of a system to support multiple behaviors, functions, and data types. OpenGIS Guide
DMA Automated Publication Production System (DAPPS) An electronic imaging device used to create text and manipulate graphic images. Output is either to a laser printer or a phototypesetter. HDBK-850
doctrine Fundamental principles by which the military forces or elements thereof guide their actions in support of national objectives. USIS 95
document (UCDM Entity: "DOCUMENT") Recorded information regardless of physical form. USIGS/CDM-A
DoD Intelligence Information System (DoDIIS) The aggregation of DoD personnel, procedures, equipment, computer programs, and supporting communications that support the timely and comprehensive preparation and presentation of intelligence and intelligence information to military commanders and national-level decisionmakers. USIS 95
DoD Intelligence Information System (DoDIIS) Integration and Engineering Support Contract A DIA-sponsored contract vehicle designed for delivery order contracts that are either fixed term price or level of effort fixed price, under the general requirement to support the DoDIIS architecture. USIS 95
dodging (photography) The process of holding back light from certain areas of sensitized material to avoid overexposure of these areas. HDBK-850
domain A permissible range of values for an attribute of a particular attribute type. CEN/TC 287
domain A concept important to interoperability, it is a distinct scope, within which common characteristics are exhibited, common rules observed, and over which a distribution transparency is preserved. CORBA 2.2
domain A well-defined set of elements. NOTE - Domains are used to define the domain set and range of set of operators. ISO/TC 211
domain A distinct functional area that can be supported by a family of systems with similar requirements and capabilities. An area of common operational and functional requirements. JTA 2.0
domain System context: A class of systems which have similar requirements and capabilities. Application context: The body of knowledge defining the range and scope of an application in terms of elements, rules and behaviors. OpenGIS Guide
domain A set of objects, each of which is related by a characterizing relationship, to a controlling object. Every domain has a controlling object associated with it. Examples of domains are Security domains and Management domains. RM-ODP
domain reference model {TC 211} A part of the ISO/TC 211 reference model that provides a high-level representation and description of the structure and content of geographic information. ISO/TC 211
domestic intelligence Intelligence relating to activities or conditions within the United States that threaten internal security and that might require the employment of troops. Also, intelligence relating to activities of individuals or agencies potentially or actually dangerous to the security of the Department of Defense. USIS 95
domestic map A map of an area within the limits of the United States. HDBK-850
dominant wavelength The wavelength of a spectrally pure energy that if mixed with white light would match a color. HDBK-850
Doppler cone angle The angle between the reference velocity vector and the reference range vector. HDBK-850
Doppler effect (JCS) The phenomenon evidenced by the change in the observed frequency of a sound or radio wave caused by a time rate of change in the effective length of the path of travel between the source and the point of observation. Also called Doppler shift. HDBK-850
Doppler navigation 1. A system which measures ground speed and drift of an aircraft, based on the Doppler effect of electronically generated signals emitted from the craft and reflected from the terrain. 2. A system which determines positions based on the Doppler effect of satellite signals. See also broadcast ephemeris; Doppler sonar navigation; Navy Navigation Satellite System; point positioning; precise ephemeris; translocation. HDBK-850
Doppler satellite survey system A receiver/antenna combination capable of receiving signals broadcast by satellites of the Navy Navigation Satellite System (NNSS). The position of the antenna is computed by point positioning, translocation, or short arc geodetic adjustment (SAGA), using the collected signals from the satellite passes. HDBK-850
Doppler shift See Doppler effect. HDBK-850
Doppler sonar navigation A system by which speed and drift of a marine craft are determined from the Doppler effect of sonar generated signals emitted from the craft and reflected from the ocean bottom or suspended particulate in the seawater. See also Doppler navigation; sonar. HDBK-850
dot screen A photographic negative containing equal-sized dots which are equally spaced in parallel and perpendicular rows. The printed area of coverage determines the screen percent. The percentage of the printed area of coverage is measured by transmission density and/or by dot diameter. Dot screens are used to print tones of a color. Also called flat tint screen. HDBK-850
double burn The intentional exposure of two or more line and/or halftone negatives in succession and register on the same sensitized surface. Not to be confused with double exposure, which is usually unintentional. Also called double shooting. See also composite. HDBK-850
double center theodolite See repeating theodolite. HDBK-850
double centering A method of prolonging a line from a fixed point whereby the backsight is taken with the telescope direct. The instrument is plunged, and the foresight is made with the telescope inverted. The point at which the vertical cross hair intersects the hub is then marked. The transit is then rotated to take a backsight on the fixed point with the telescope inverted, the foresight is made with the telescope direct, and a second projected point is marked on the hub. A point midway between the two marked points is the true point on the prolonged line. Also called double reversing; double reversion; double sighting; reversing in azimuth and altitude; wiggling-in on a line; working-in on a line. HDBK-850
double corners Normally the two sets of corners along a standard parallel; the standard township, section, and quarter section corners placed at regular intervals of measurement; additionally, the closing corners established on the line at the points of intersection of the guide meridians, range, and section lines of the surveys brought in from the south. In other cases, not fully in conformity with the rectangular plan, two corners, each common to two townships only, instead of one corner of the four townships. Similarly, two corners, each common to two sections, and two quarter section corners, each referring to one section only. The term is sometimes used incorrectly to denote two lines established on the ground although the field note record indicates only one line, thus creating a hiatus or overlap. HDBK-850
double enveloping A technique consisting of encasing the content and envelope of a message in a new outer envelope to protect the information on the envelope whenever a message is forwarded through a less trusted domain. The content of the new outer envelope may or may not be encrypted, depending o the degree of trust accorded to the less trusted domain. [DISA/D2] DISA CFS
double exposure Two photographic exposures on the same sensitized surface. HDBK-850
double interpolation Deriving a value from tabulated computations where two or three proportions may be required, as in an hour angle observation of Polaris for azimuth, where an interpolation is made suitable to the time factor, another to arrive at a result conforming with the latitude of the observing station. HDBK-850
double meridian distance The algebraic sum of the perpendicular distances from the two ends of any line of a traverse to the initial, or reference, meridian. HDBK-850
double model stereotemplet A templet representative of the horizontal plot of two or three adjacent stereoscopic models that have been adjusted to a common, though random, scale. HDBK-850
double optical projection stereo-plotter See double-projection direct-viewing stereoplotter. HDBK-850
double proportionate measurement A method for restoring a lost corner of four townships or a lost interior corner of four sections. It is based on the principle that monuments north and south should control the latitudinal position of a lost corner, and monuments east and west should control the longitudinal position. In this method the influence of one identified original corner is balanced by the control of a corresponding original corner upon the opposite side of a particular missing corner which is to be restored, each identified original corner being given a controlling weight inversely proportional to its distance from the lost corner. HDBK-850
double reversing See double centering. HDBK-850
double reversion See double centering. HDBK-850
double shooting See double burn. HDBK-850
double sighting See double centering. HDBK-850
double target leveling rod Any target rod having graduations on two opposite faces. HDBK-850
double zenith distance A value of twice the zenith distance of an object, obtained by observation and not by mathematical process. HDBK-850
double-projection direct-viewing stereoplotter A class of stereo-plotters employing the principle of projecting the images of two correctly oriented overlapping aerial photographs onto a reference datum so the resultant images may be viewed directly without additional optical system support. Also called double optical projection stereoplotter. HDBK-850
double-rodded line A line of differential levels wherein two sets of turning points, one high and one low, are used to give independent measures between bench marks. HDBK-850
doubly azimuthal map projection An azimuthal map projection having two poles. HDBK-850
dove prism A prism which reverts the image but does not deviate or displace the beam. A given angular rotation of the prism about its longitudinal axis causes the image to rotate through twice the angle. Also called rotating prism. HDBK-850
DPPDB Exploitation Workstation Drop Software (DEW_Drop) DEW_Drop was developed by the National Imagery and Mapping Agency (NIMA) for Digital Point Positioning Data Base (DPPDB) engineering development and prototype analysis. DEW_Drop is used to view DPPDB imagery and to perform point mensuration. NIMA Web Site
draconic month See nodical month. HDBK-850
drafting The art of drawing from given specifications. HDBK-850
drafting guide See guide. HDBK-850
drag (theodolite) A slight movement of the graduated circle of a theodolite produced by the rotation of the alidade. See also atmospheric drag. HDBK-850
drag The effect of the atmosphere on satellites. The density of the Earth's atmosphere is greatest at sea level and decreases with increasing altitude. Atmosphere has a perceptible effect on satellite orbits as high as 500 NM above the earth's surface. The density of the atmosphere causes satellites to decrease their velocity. This effect is called drag. Large lightweight satellites are more effected by drag than small, heavy satellites. Low altitude satellites are more effected by drag than high altitude satellites. Drag is a dominant effect for satellites with perigees lower than 90NM and may cause the satellite to "reenter" if no corrective measures are taken. Perigees lower than 80NM are usually impractical due to drag. The effects of drag can be negated by periodic orbit correction maneuvers. USIS 95
drainage In mapping, all features associated with water, such as shorelines, rivers, lakes, marshes, etc. HDBK-850
drainage pattern The pattern or overall appearance made by the network of drainage features on a map or chart. HDBK-850
drawing interchange format (DXF) A file exchange format developed by Autodesk Inc. for its AutoCAD drafting software. DXF files are ASCII records of all objects in a drawing file. DXF has been adopted more recently by GIS systems for exchanging map files. OpenGIS Guide
drift 1. (JCS) In ballistics, a shift in projectile direction due to gyroscopic action which results from gravitational and atmospherically induced torques on the spinning projectile. 2. The lateral shift or displacement of a ship or aircraft from its course, due to the action of wind or other causes. 3. Aerial photography obtained under this condition produces successive photographs whose edges are parallel but sidestepped. 4. (precession) See total drift. HDBK-850
drift angle (JCS) The angle measured in degrees between the heading of an aircraft or ship and the track made good. [Drift angle is designated right or left to indicate the direction of drift.] HDBK-850
drift station A term sometimes used in shoran operations to designate the ground station about which the aircraft flies during arc navigation. The second ground station is then referred to as the rate station. HDBK-850
drone A land, sea, or air vehicle that is remotely or automatically controlled. USIS 95
dummy 1. A preliminary drawing or layout showing the position of illustrations and text as they will appear in the final reproduction. 2. A set of blank pages made up to show the size, shape, and general style of a book, booklet, or pamphlet. HDBK-850
dummy pendulum A pendulum of similar construction to the working pendulums except that it is equipped with a thermometer and is fastened rigidly in the receiver so that it cannot swing during observations. The dummy pendulum is subject to the same temperature conditions as the working pendulums, and is used in determining their temperature when in use. HDBK-850
dumpy level A leveling instrument which has its telescope permanently attached to the leveling base, either rigidly or by a hinge that can be manipulated by a micrometer screw. HDBK-850
duplex base-line measuring apparatus A contact base-line measuring apparatus, composed of two disconnected bars, one of brass and the other of steel, each 5 meters in length and so arranged as to indicate the accumulated difference of length of the measures from the brass and steel components. HDBK-850
duplicate level line A line of spirit leveling composed of two single lines run over the same route, but in opposite directions, and using different turning points. HDBK-850
duplicate negative (JCS) A negative reproduced from an original negative or diapositive. [The duplicate negative may be a true reproduction of the original or a reproduction possessing greater or less contrast. With direct positive materials, chemical reversal process, and duplicating film it is not always necessary to make a positive to obtain a duplicate negative.] HDBK-850
duplicate positive A hardcopy image that is reproduced directly from the original negative. Often referred to as a "dup pos." USIS 95
duration The amount of time during a geographic access when all of the specified access conditions are satisfied. USIS 95
dylux A light-sensitive paper or film used for proofing, usually has a blue positive reading image with a blue background. HDBK-850
dynamic correction The quantity that must be added to the orthometric elevation of a point to obtain its dynamic number. HDBK-850
dynamic elevation Elevation expressed in length units, but determined by dynamic number. HDBK-850
dynamic gravity meter A type of gravity instrument in which the period of oscillation is a function of gravity and is the quantity directly observed. HDBK-850
dynamic height A height derived by dividing the geopotential number by a constant, usually the value of normal gravity at 45 latitude. HDBK-850
dynamic invocation Constructing and issuing a request whose signature is possibly not known until runtime. CORBA 2.2
dynamic number The work required to raise a unit mass from sea level to a given point, expressed in absolute units. HDBK-850
dynamic range The spread of gray values found in a given image. High dynamic range implies a wide spread of gray values whereas low dynamic range indicates a small spread and, therefore, low contrast. The dynamic range of a digital image relates to the number of bits per pixel (BPP), usually 8 to 12 with 12 providing the greater potential for dynamic range adjustment or image processing enhancement. USIS 95
dynamic range adjust The mathematical process by which the tones of reproduced imagery are adjusted to compensate for the adverse effect of imaging through the atmosphere. USIS 95
dynamic segmentation Points along a line that vary in value, e.g. pavement thickness along a road centerline. OpenGIS Guide
dynamic skeleton An interface-independent kind of skeleton, used by servers to handle requests whose signatures are possibly not known until runtime. CORBA 2.2
dynamic temperature correction (pendulum) The correction to the observed period of a pendulum for the rate of change of its temperature. HDBK-850
dynamical mean sun A fictitious sun conceived to move eastward along the ecliptic at the average rate of the apparent sun. HDBK-850
dyne The dyne is the unit of force of the c.g.s. systems of units. When acting on a mass of 1 gram, a dyne imparts to that mass an acceleration of 1 centimeter per second per second. Until about 1930, the dyne was used by the U.S. Coast and Geodetic Survey (now the National Geodetic Survey) in stating values of gravity. Since that time, gravity has been reported in terms of the gal, the c.g.s. unit of acceleration. HDBK-850

Last Updated by Mark Owens 17 February 1999.