# ERS -- ERMapper .ERS

GDAL supports reading and writing raster files with .ers header files, with some limitations. The .ers ascii format is used by ERMapper for labeling raw data files, as well as for providing extended metadata, and georeferencing for some other file formats. The .ERS format, or variants are also used to hold descriptions of ERMapper algorithms, but these are not supported by GDAL.

Starting with GDAL 1.9.0, the PROJ, DATUM and UNITS values found in the ERS header are reported in the ERS metadata domain.

## Creation Issues

Creation Options:

- PIXELTYPE=value:.By setting this to SIGNEDBYTE, a new Byte file can be forced to be written as signed byte

- PROJ=name: (GDAL >= 1.9.0) Name of the ERS projection string to use. Common examples are NUTM11, or GEODETIC. If defined, this will override the value computed by SetProjection() or SetGCPs().

- DATUM=name: (GDAL >= 1.9.0) Name of the ERS datum string to use. Common examples are WGS84 or NAD83. If defined, this will override the value computed by SetProjection() or SetGCPs().

- UNITS=name: (GDAL >= 1.9.0) Name of the ERS projection units to use : METERS (default) or FEET (us-foot). If defined, this will override the value computed by SetProjection() or SetGCPs().

## See Also:

- Implemented as `gdal/frmts/ers/ersdataset.cpp`.