Enterprise Spatial Solutions

Application

An off the shelf or custom program you are using which allows you to access geographic information to enable business decisions or analysis.

Area

The level of spatial measurement referring to a two-dimensional defined space; for example, a polygon on the earth as projected onto a horizontal plane.

Attribute

1. A numeric, text, or image data field in a relational data base table that describes a spatial feature such as a point, line, node, area or cell. 2. A characteristic of a geographic feature described by numbers or characters, typically stored in tabular format, and linked to the feature by an identifier. For example, attributes of a well (represented by a point) might include depth, pump type, location, and gallons per minute.

AM/FM

Automated Mapping/Facilities Management. A GIS designed primarily for engineering and utility purposes, AM/FM is a system that manages databases related to spatially distributed facilities.

Automated Information System (AIS)

Computer hardware, computer software, telecommunications, information technology, personnel, and other resources that collect, record, process, store, communicate, retrieve, and display information. An AIS can include computer software only, computer hardware only, or a combination of the above.

Base Map

A map showing planimetric, topographic, geological, political, and/or cadastral information that may appear in many different types of maps. Base map information may be as simple as major political boundaries, major hydrographic data, or major roads. The changing thematic information may be bus routes, population distribution, or caribou migration routes.

Base Station

A GPS receiver on a known location that may broadcast and/or collect correction information for GPS receivers on unknown locations.

CADD

Computer-Aided Design and Drafting. Any system for computer-aided rather than manual drafting and design. Displays data spatially on a predefined coordinate grid system, allowing data from different sources to be connected and referenced by location. CADD accelerates conventional map development process by: 1. Permitting replication of shapes, floor plans, etc. from an electric library rather than requiring every component to be drawn from scratch. 2. Plotters and terminal screens are faster and more accurate than manual drafting. 3. Portions of drawings can be edited, enlarged, etc. quickly. 4. Related information can be stored in files and added to drawings in layers.

CAD

Computer-Aided Dispatching. Used with emergency vehicles, CAD can be very sophisticated. Online maps of a city can display emergency vehicles as moving dots on the map, their status (enroute to an emergency, awaiting a call, call completed, returning to base, etc.) indicated by different colors. (The acronym for computer-aided dispatch is sometimes confused with computer-aided design.)

Centroid

The geographic center of any polygon.

Clearinghouse

A physical repository structure used to accumulate and disseminate digital data and information concerning that data. In the GIS context a clearinghouse can contain all or a portion of spatial, metadata and attribute data.

Commercial-Off-
the-Shelf (COTS)

Refers to an item of hardware or software that has been produced by a contractor and is available for general purchase. Such items are at the unit level or higher. Such items must have been sold and delivered to government or commercial customers, must have passed customer's acceptance testing, and must be operating under the customer's control and within the user environment. Further, such items must have meaningful reliability, maintainability, and logistics historical data.

Coordinate

The position of point is space in respect to a Cartesian coordinate system (x, y and/or z values). In GIS, a coordinate often represents locations on the earth's surface relative to other locations.

Database

Usually a computerized file or series of files of information, maps, diagrams, listings, location records, abstracts, or references on a particular subject or subjects organized by data sets and governed by a scheme of organization. "Hierarchical" and relational" define two popular structural schemes in use in a GIS.

Data Providers

Companies that gather digital map data from a variety of public or private sources and adapt it for a use within GIS application software for sales and marketing analysis of customers or prospects.

Digital Elevation Model (DEM)

A data model consisting of terrain (or bathymetric) elevations recorded at the intersections of an evenly spaced, fine grid. Often used to generate contour (hypsometric) lines.

Differential Correction

The method (usually done through post processing) of using two GPS receivers, one on a known location and one on an unknown location, using information from the one on the known location to correct the position of the unknown location.

Digital Orthophoto

A geographically correct digital image generated from aerial photographs.

Digitizer

A device used to capture planar coordinate data, usually as x and y coordinates, from existing analog maps for digital use within a computerized program such as a GIS.

Enumeration Area (EA)

Refers to the geographic area canvassed by one census representative. It is the smallest geographic area for which census data is reported. An Enumeration Area may contain approximately 125 to 440 dwellings depending on whether it is located in a rural or urban area respectively.

Geocode

The process of identifying a location as one or more x, y coordinates from another location description such as an address. For example, an address for a student can be matched against a TIGER street network to locate the student's home.

Geographic Information System (GIS)

An organized collection of computer hardware, software, data, personnel, and procedures designed to efficiently capture, store, update, manipulate, analyze, and display all forms of geographically referenced information. Certain complex spatial operations are possible with a GIS that would be very difficult, time-consuming, or otherwise impractical.

Geospatial

A term used to describe a class of data that has a geographic or spatial nature.

Geostationary Satellite

An earth satellite that remains in fixed position, in sync with the earth's rotation.

Global Positioning System (GPS)

A system developed by the U.S. Department of Defense based on 24 satellites orbiting the Earth. Inexpensive GPS receivers can accurately determine ones position on the Earth's surface.

GCP

Ground Control Point. A point on the Earth's surface of known location that is visually observable from either air or space. Used to geo-reference image data sources, such as remotely sensed images or scanned maps.

Geo-Locational Accuracy

The degree to which the coordinates of points determined from a geospatially referenced image or dataset agree with the coordinates determined by ground survey or other independent, higher-accuracy means.

Georeference

To establish the relationship between page coordinates on a paper map or manuscript and known real world coordinates.

Information Management

The planning, budgeting, manipulating, controlling of information throughout its life-cycle (e.g., creation or collection, processing, dissemination, use, storage, and disposition).

Information Resources Management

The process of managing information resources to accomplish agency missions. The term encompasses both information itself and the related resources such as personnel, equipment, funds, and information technology.

Layers

A means of organizing and managing map data by type. Hydrological features (such as floodplains), parcel maps, railroads, and so on can be contained on separate layers for easy map creation and maintenance.

Map Projection

A mathematical model for converting locations on the earth's surface from spherical to planar coordinates, allowing flat maps to depict three dimensional features. Some map projections preserve the integrity of shape; others preserve accuracy of area, distance, or direction.

Metadata

Data describing a GIS database or data set including, but not limited to, a description of a data transfer mediums, format, and contents, source lineage data, and any other applicable data processing algorithms or procedures.

Multispectral Imagery

Also commonly referred to as "color" imagery. The use of one or more imaging sensors to obtain imagery from different portions of the electromagnetic spectrum.

Natural Color Imagery

A three-band image combining red, green and blue bands of data.

NGA

National Geospatial Intelligence Agency: NGA is a member of the U.S. Intelligence Community and a Department of Defense Combat Support Agency. The organization provides timely, relevant and accurate geospatial intelligence in support of national security objectives.

Off-Nadir

Any point that is not directly below a sensor, but off to an angle in any direction.

Orthorectified Imagery

Imagery from which distortions due to varying elevation, tilt, and surface topography have been removed, so that the image represents every object on the ground as if viewed directly from above.

Orthophoto

A photograph of the earth's surface in which geographic distortion has been removed.

Photogrammetry

The art or process of aerial photography combined with precise measurements to produce accurate maps.

Planimetric Map

A map which represents the horizontal positions of real world geospatial features; distinguished from a topographic map by the omission of relief in measurable form. The natural features usually shown on a planimetric map include rivers, lakes and seas; mountains, valleys and plains; and forests, prairies, marshes and deserts. The cultural features include cities, farms, transportation routes and public-utility facilities; and political and private boundary lines.

Raster Data

Machine-readable data that represent values usually stored for maps or images and organized sequentially by rows and columns. Each "cell" must be rectangular but not necessarily square, as with grid data.

Rectify

The process by which an image or grid is converted from image coordinates to real-world coordinates. Rectification typically involves rotation and scaling of grid cells, and thus requires resampling of values.

Relational Database Management System (RDBMS)

A database management system with the ability to access data organized in tabular files that may be related together by a common field.

Remote Sensing

Recording imagery or data and information from a distance. Photography is a form of remote sensing. Satellites provide a remote sensing platform for developing geology and soils analysis with sensors sensitive to various bands of the electromagnetic spectrum.

Resolution

Also called spatial resolution, it represents the dimension of the smallest area depicted in the image. Higher resolution means more spatial detail.

Revisit Capability

The frequency with which a satellite is able to fly over the same geographic area to repeatedly capture imagery.

Scale

The relationship between a distance on a map and the corresponding distance on the earth. Often used in the form 1:24,000, which means that one unit of measurement on the map equals 24,000 of the same units on the earth's surface. Scale can also be represented as 1"=200', meaning 1 inch on the map is equal to 200 feet on the earth's surface.

Spatial Data

Data pertaining to the location of geographical entities together with their spatial dimensions. Spatial data are classified as point, line, area, or surface.

Spatial Model

Analytical procedures applied with a GIS. There are three categories of spatial modeling functions that can be applied to geographic data objects within a GIS: (1) geometric models (such as calculation of Euclidian distance between objects, buffer generation area, and perimeter calculation); (2) coincidence models (such as a polygon overlay); and (3) adjacency models (pathfinding, redistricting, and allocation). All three model categories support operations on geographic data objects such as points, lines, polygons, TlNs, and grids. Functions are organized in a sequence of steps to derive the desired information for analysis.

Swath Width

The cross-track width of an image defined by the camera's field of view. If the satellite's swath width is 60 km then a satellite image scene will usually be delivered as a 60 km x 60 km image.

Systems Architecture

Defines the physical connection, location, and identification of key nodes, circuits, networks, warfighting platforms, etc. and specifies system and component performance parameters. The systems architecture is constructed to satisfy operational architecture requirements per standards defined in the technical architecture. The systems architecture shows how multiple systems within a subject area link and interoperate, and may describe the internal construction or operations of particular systems within the architecture.

Technical Architecture

The technical architecture identifies the services, interfaces, standards, and their relationships. It provides the technical guidelines for implementation of systems upon which engineering specifications are based, common building blocks are built, and product lines are developed.

Topology

The spatial relationships between connecting or adjacent features (e.g., arcs, nodes, polygons and points.

Transformation

The process of converting data from one coordinate system to another through translation, rotation, and scaling.

Vector Data

A coordinate-based data structure commonly used to represent map features.