erial Photography - The process of taking photography from an aircraft using specialized photographic equipment.

ase Map - A map on which information can be placed for geographical correlation. Also can be used as a "base" upon which to build other information. Digital Orthophotography serves as an excellent base map due to its accuracy and visual characteristics.

adastral Map - A map defining land ownership information. Generally used for taxation, planning, zoning and site development. Often serve as the base map for a Land Information System (LIS).

ontour Interval - The difference in elevation of two adjacent contour lines. Typical Contour Intervals are 1', 2', 5' and 10'.

ata Dictionary - A document that contains features, rules and item definitions for a specific set of geospatial data.

igital Orthophotography - A photo-quality digital image of surface features in their geometrically corrected, true map projection. The orthorectification process ties each pixel in a digital image to its true Earth location.

eographic Information System (GIS) - A geographic information system (GIS), also known as a geographical information system or geospatial information system, is any system for capturing, storing, analyzing, managing and presenting data and associated attributes which are spatially referenced to Earth

lobal Positioning System (GPS) - A group (constellation) of 24 satellites maintained by the U.S. Department of Defense that are used to triangulate the true position on the Earth's surface of a specific GPS receiver.

and Information System (LIS) - Similar to a GIS, an LIS is designed specifically to create, visualize, analyze, report and publish land-based data such as parcel information, zoning, land use, ownership and general property information.

iDAR (Light Detection and Ranging) - This remote-sensing technique uses lasers to measure the distances from reflective surfaces. The information captured produces an image comparable to a coarse photograph. Digital elevation models(DEMs) designating bare-earth, vegetation, undergrowth, tree canopy and buildings are produced, and when overlaid with Orthophotographs, a 3-D, naturally colored and detailed represention of your area or region can be rotated, viewed by all angles and virtually manipulated in a multiple of ways.

etadata - Formal documentation describing the characteristics of a specific geospatial data set.

rthophotography - Orthophotography is an aerial photograph that has been corrected of distortions attributable to camera tilt and ground relief. Orthophotographs are used as a data source for mapping geographic features and enviornmental conditions.

hotogrammetry - Photogrammetry, or remote sensing, is the technique of measuring objects (two or three-dimensionally) via overlapping photographs. Aerial photogrammetry is used to produce topographical or theme maps, while close-range photogrammetry can be used, for example, to supervise buildings or guide police, plastic surgeons and architects. In our work at TGMG, we utilize both technologies.

lanimetric Feature - Features of a map that represent everything except relief; both man-made and natural features like vegetation are considered planimetric. Examples include building footprints, edge of street pavement, sidewalks, etc.

tereo Compilation - The process of mapping planimetric and/or topographic data in a 3-D environment from two overlapping.

riangular Irregular Network - A triangulated irregular network (TIN) is a digital data structure used in a geographic information system (GIS) for the representation of a surface. A TIN is a vector based representation of the physical land surface or sea bottom, made up of irregularly distributed nodes and lines with three dimensional coordinates (x,y, and z) that are arranged in a network of nonoverlapping triangles.

opographic Feature - The features of a map that represent the natural features of the Earth's surface; representing relief. Those features collectively form a "model" of the surface.

opology - Topology is a mathematical procedure for explicitly defining spatial relationships. Topology expresses different types of spatial relationships as features (e.g., polygon features for areas and lines for linear features).