A GIS file format is a standard of encoding geographical information into a file. They are created mainly by government mapping agencies (such as the USGS) or by GIS software developers.
Metadata often includes:
- Elevation data, either in raster or vector form (e.g., contours)
- Shape layers, usually expressed as line drawings, for streets, postal zone boundaries, etc.
- Coordinate system descriptions.
- One or more datums describing the precise shape of the Earth assumed by the coordinates.
Popular GIS file formats
- USGS DEM - US Geo Survey Digital Elevation Model
- SDTS - The USGS' successor to DEM
- BIL - Binary Interleave
- GTOPO30 - Large "complete Earth" coverage filesets
- XYZ - Simple point cloud
- GeoTIFF - TIFF variant expressly for GIS data
- NTF - UK Ordnance Survey
- ASC - Simple ASCII text point cloud format
- UKOS DXF Contour - Contour elevation plots in DXF format
- ESRI SHP (Shape) - Cartographic vector data with database table lookup association (using DBF and SHX files)
- BT - The Virtual Terrain Project's Binary Terrain format
