Frequently asked Questions

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Frequently asked Questions

Terms

Anaglyph

Anaglyph images are used to provide a stereoscopic 3d effect, when viewed with 2 color paper or plastic glasses. Images are made up of two layers, superimposed, that are slightly offset,contain two differently filtered colored images, one for each eye. When viewed through the "color coded" "anaglyph glasses" , they reveal an integrated stereoscopic image. The visual cortex of the brain fuses this into perception of a three dimensional scene or composition.

ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer)

ASTER is one of five remote sensory devices on board the Terra satellite launched into Earth orbit by NASA in 1999. The instrument has been collecting data since February 2000. ASTER provides high-resolution images of the Earth in 14 different wavelengths of the electromagnetic spectrum, ranging from visible to thermal infrared light. The resolution of images ranges between 15 to 90 meter. ASTER data is used to create detailed maps of surface temperature of land, emissivity, reflectance, and elevation.

Bits

The bit depth (or pixel depth) of a cell determines the range of values that a particular raster file can store, which is based on the formula 2n (where n is the bit depth). For example, an 8-bit raster can have 256 unique values, which range from 0 to 255.

DEM - Digital Elevation Model

A digital elevation model (DEM) is a type of Digital terrain model, recording a topographical (geomorphometric) representation of the terrain of the Earth or another surface in digital format. DEM's record altitude in a raster format. That is, the map will normally divide the area into rectangular pixels and store the elevation of each pixel. In that sense, digital elevation model (DEM) data are sampled arrays of surface elevations in raster form.[1] DEMs are used often in geographic information systems, and are the most common basis for digitally-produced relief maps.

GeoTIFF

GeoTIFF is a public domain metadata standard which allows georeferencing information to be embedded within a TIFF file. The potential additional information includes projections, coordinate systems, ellipsoids, datums, and everything else necessary to establish the exact spatial reference for the file. The GeoTIFF format is fully compliant with TIFF 6.0, so software incapable of reading and interpreting the specialized metadata will still be able to open a GeoTIFF file.

GOOGLE EARTH

Google Earth is a virtual globe program that was originally called Earth Viewer and was created by Keyhole, Inc. It maps the earth by the superimposition of images obtained from satellite imagery, aerial photography and GIS over a 3D globe. It is available under three different licenses: Google Earth, a free version with limited functionality; Google Earth Plus, which includes a few more features; and Google Earth Professional, intended for commercial use.

ORTHOIMAGE

An orthoimage or orthophotoimage is an satellite imagery that has been geometrically corrected ("orthorectified"). An orthoimages can be used to measure true distances, because it is an accurate representation of the earth's surface, having been adjusted for topographic relief.

TNTlite

TNTlite is a free geospatial analysis system providing a complete fully featured Geographic information system, RDBMS, and automated image processing system with CAD, TIN, surface modeling, map layout and innovative data publishing tools. All this capability is available in a single integrated system with an identical interface, functionality, and geodata structure for use on Mac OS X, Windows, Sun Solaris, and popular Linux platforms. The interface, database text content, messages, map production, and all other internal aspects of TNTmips have been localized for use in numerous languages including Japanese, Chinese, Arabic, Turkish. Thai, German, Spanish, French and others. The professional version of the TNTmips is in use in over 120 nations while the free TNTlite version (restricted in project size) is used in almost every nation for educational, self learning, and small projects (e.g., archaeological sites, neighborhood planning, and precision farming). The product includes free tutorials and application booklets with step-by-step lessons.

TNTmips

TNTmips is a geospatial analysis system providing a fully featured GIS, RDBMS, and automated image processing system with CAD, TIN, surface modeling, map layout and innovative data publishing tools. TNTmips has a single integrated system with an identical interface, functionality, and geodata structure for use on various operating system. The interface, database text content, messages, map production, and all other internal aspects of TNTmips have been localized for use in many languages, including, for example Arabic, Thai, and all romance languages. The professional version of the TNTmips is in use in over 120 nations while the free TNTlite version (restricted in project size) is used in world-wide for educational, self learning, and small projects (e.g., archaeological sites, neighborhood planning, and precision farming).