GIS file formats

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 National Geospatial-Intelligence Agency) or by GIS software developers.

Metadata often includes:

• Elevation data, either in raster or vector (e.g., contour lines) form
• Shape layers, usually expressed as line drawings, for streets, postal zone boundaries, etc.
• Coordinate system descriptions.
• One or more data describing the precise shape of the Earth assumed by the coordinates.

Popular GIS file formats

Raster formats

• ADRG - National Geospatial-Intelligence Agency (NGA)'s ARC Digitized Raster Graphics
• BIL - Band Interleaved by Line (image format linked with satellite derived imagery)
• CADRG - National Geospatial-Intelligence Agency (NGA)'s Compressed ARC Digitised Raster Graphics (nominal compression of 55:1 over ADRG)
• ECRG - National Geospatial-Intelligence Agency (NGA)'s Enhanced Compressed ARC Raster Graphics (Better resolution than CADRG and no color loss)
• CIB - National Geospatial-Intelligence Agency (NGA)'s Controlled Image Base (type of Raster Product Format)
• Digital raster graphic (DRG) - digital scan of a paper USGS topographic map
• ECW - Enhanced Compressed Wavelet (from ERDAS). A compressed wavelet format, often lossy.
• Esri grid - proprietary binary and metadataless ASCII raster formats used by Esri
• GeoTIFF - TIFF variant enriched with GIS relevant metadata
• IMG - ERDAS IMAGINE image file format
• JPEG2000 - Open-source raster format. A compressed format, allows both lossy and lossless compression.
• MrSID - Multi-Resolution Seamless Image Database (by Lizardtech). A compressed wavelet format, often lossy.
• netCDF-CF - netCDF file format with CF medata conventions for earth science data. Binary storage in open format with optional compression. Allows for direct web-access of subsets/aggregations of maps through OPeNDAP protocol.

Vector formats

See Also Comparison of Vector Formats (GIS)

• Geography Markup Language (GML) - XML based open standard (by OpenGIS) for GIS data exchange
• Keyhole Markup Language (KML) - XML based open standard (by OpenGIS) for GIS data exchange
• AutoCAD DXF - Contour elevation plots in AutoCAD DXF format
• Shapefile - Esri's open, hybrid vector data format using SHP, SHX and DBF files
• Simple Features - Open Geospatial Consortium specification for vector data
• MapInfo TAB format - MapInfo's vector data format using TAB, DAT, ID and MAP files
• National Transfer Format (NTF) - National Transfer Format (mostly used by the UK Ordnance Survey)
• TIGER - Topologically Integrated Geographic Encoding and Referencing
• Cartesian coordinate system (XYZ) - Simple point cloud
• Vector Product Format - National Geospatial-Intelligence Agency (NGA)'s format of vectored data for large geographic databases.
• GeoMedia - Intergraph's Microsoft Access based format for spatial vector storage.
• ISFC - Intergraph's MicroStation based CAD solution attaching vector elements to a relational Microsoft Access database
• Personal Geodatabase - Esri's closed, integrated vector data storage strategy using Microsoft's Access MDB format
• File Geodatabase - Esri's file-based geodatabase format, stored as folders in a file system. Esri also has an enterprise Geodatabase format for use in an RDBMS.
• Coverage - Esri's closed, hybrid vector data storage strategy. Legacy ArcGIS Workstation / ArcInfo format with reduced support in ArcGIS Desktop lineup
• Spatial Data File - Autodesk's high-performance geodatabase format, native to MapGuide
• GeoJSON - a lightweight format based on JSON, used by many open source GIS packages
• SOSI_Standard - a spatial data format used for all public exchange of spatial data in Norway
• Digital Line Graph (DLG) - a USGS format for vector data

Grid formats (for elevation)

• USGS DEM - The USGS' Digital Elevation Model
• DTED - National Geospatial-Intelligence Agency (NGA)'s Digital Terrain Elevation Data
• GTOPO30 - Large complete Earth elevation model at 30 arc seconds
• SDTS - The USGS' successor to DEM

Other formats

• Binary Terrain (BT) - The Virtual Terrain Project's Binary Terrain format
• Dual Independent Map Encoding (DIME) – A historic GIS file format, developed in the 1960s
• Well-known text (WKT) – ASCII spatial projection description (Esri uses a *.prj extension)
• Well-known binary (WKB) - Binary spatial projection description
• World file - Georeferencing a raster image file (e.g. JPEG, BMP)

See also

• Computer file
• Datum (geodesy)
• GDAL/OGR, a library for reading and writing many formats
• Geoinformation
• Geography portal

External links

• Geo Community - GIS Data Formats
• GIS Lounge
• Safe Software's list of (FME Suppported) GIS Data Formats