Digital Feature Analysis Data

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Digital Feature Analysis Data ( DFAD ) is a collection of digital cartographic data from the US Defense Mapping Agency (DMA) (incorporated into the National Geospatial-Intelligence Agency ). As part of the Digital Land Mass System ( DLMS ), it supplements the topographical information of the DTED library with data on surface features such as vegetation, structures and infrastructure.

DFAD files contain a digital object model that includes the objects that are on the digital terrain model .

The digital object data are saved as vector data and are divided into point, line and area objects. The coordinate resolution is one arc second .

Among other things, the data contains an entry for the object type and one for the surface texture. There are around 1,000 different object types in total.

The files can cover different areas. Within Germany they are 12 × 20 arc minutes in size. At the borders and outside of Germany, the size of the data tiles varies from larger than 12 × 20 minutes of arc to a 1 × 1 degree block.

The World Geodetic System 1984 (WGS84) is mostly used as the horizontal datum, but it is also possible that the WGS72 is used in older files .

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