Supported CRSs and Their Configuration

This section describes configuration of Coordinate Reference Systems for both WMS and WCS services.

Coordinate Reference Systems

The Coordinate Reference System (CRS) denotes the projection of coordinates to an actual position on Earth. EOxServer allows the configuration of supported CRSes for WMS and WCS services. The CRSes used by EOxServer are specified exclusively by means of EPSG numerical codes.

Web Map Service

EOxServer allows the specification of the overall list of CRSes supported by all published map layers (listed at the top layer of the WMS Capabilities XML document). In case of no common CRS the list can be empty. In addition to the list of common CRSes each individual layer has its native CRS which need not to be necessarily listed among the common CRSes. The meaning of the native CRS changes based on the EO dataset:

  • Rectified Datasets - the actual CRS of the source geo-rectified raster data,
  • Rectified Stitched Mosaic - the actual CRS of the source geo-rectified raster data,
  • Referenceable Dataset - the CRS of the geo-location grid tie-points.
  • Time Series - always set to WGS 84 (may be subject to change in future).

This native CRS is also used as the CRS in which the geographic extent (bounding-box) is published.

The list of WMS common CRSes is specified as a comma separated list of EPSG codes in the EOxServer’s configuration (<instance path>/conf/eoxserver.conf) in section serices.ows.wms:

supported_crs= <EPSG-code>[,<EPSG-code>[,<EPSG-code> ... ]]

Web Coverage Service

EOxServer allows the specification of a list of CRCes to be used by the WCS. These CRSes can be used to select subsets of the desired coverage or, in case of rectified datasets (including rectified stitched mosaics) to specify the CRS of the output image data. The latter case is not applicabe to referenceable datasets as these are always returned in the original image geometry.

The list of WCS supported CRSes is specified as a comma-separated list of EPSG codes in the EOxServer configuration (<instance path>/conf/eoxserver.conf) in section serices.ows.wcs:

supported_crs= <EPSG-code>[,<EPSG-code>[,<EPSG-code> ... ]]