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- .. _wcs_vendor_parameters:
- WCS Vendor Parameters
- =====================
- WCS vendor parameters are non-standard request parameters
- that are defined by an implementation to provide enhanced capabilities.
- .. include:: ../generic_vendor_options.txt
- GetCoverage Request
- -------------------
- namespace
- ^^^^^^^^^
- Requests to the WCS GetCapabilities operation can be filtered to only return layers corresponding to a particular namespace.
- Sample code: ::
- http://example.com/geoserver/wcs?
- service=wcs&
- version=1.0.0&
- request=GetCapabilities&
- namespace=topp
- Using an invalid namespace prefix will not cause any errors, but the document returned will not contain information on any layers.
- cql_filter
- ^^^^^^^^^^
- The ``cql_filter`` parameter is similar to same named WMS parameter, and allows expressing a filter using ECQL (Extended Common Query Language).
- The filter is sent down into readers exposing a ``Filter`` read parameter.
- For example, assume a image mosaic has a tile index with a ``cloudCover`` percentage attribute, then it's possible to mosaic only
- granules with a cloud cover less than 10% using:
- cql_filter=cloudCover < 10
- For full details see the :ref:`filter_ecql_reference` and :ref:`cql_tutorial` tutorial.
- sortBy
- ^^^^^^
- The ``sortBy`` parameter allows to control the order of granules being mosaicked, using the same
- syntax as WFS 1.0, that is:
- * ``&sortBy=att1 A|D,att2 A|D, ...``
- This maps to a "SORTING" read parameter that the coverage reader might expose (image mosaic exposes such parameter).
- In image mosaic, this causes the first granule found in the sorting will display on top, and then the others will follow.
-
- Thus, to sort a scattered mosaic of satellite images so that the most recent image shows on top, and assuming the time attribute is called ``ingestion`` in the mosaic index, the specification will be ``&sortBy=ingestion D``.
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