WPS Download NetCDF¶

Installing the WPS Download NetCDF module¶

The WPS Download NetCDF module depends on 3 extensions:

• Web Processing Service (WPS)

• WPS Download

• NetCDF Output Format

To install:

1. Login, and navigate to About & Status > About GeoServer and check Build Information to determine the exact version of GeoServer you are running.

2. Visit the website download page, change the Archive tab, and locate your release.

   From the list of OGC Services extensions download WPS.

   • 2.28.0 example: geoserver-2.28.0-wps-plugin.zip

   • 3.0-SNAPSHOT example: geoserver-3.0-SNAPSHOT-wps-plugin.zip

   From the list of OGC Services extensions download WPS Download.

   • 2.28.0 example: geoserver-2.28.0-wps-download-plugin.zip

   • 3.0-SNAPSHOT example: geoserver-3.0-SNAPSHOT-wps-download-plugin.zip

3. From the list of Output Formats extensions download NetCDF.

   • 2.28.0 example: geoserver-2.28.0-netcdf-out-plugin.zip

   • 3.0-SNAPSHOT example: geoserver-3.0-SNAPSHOT-netcdf-out-plugin.zip

4. Visit the website download page, change the Development tab, and locate the nightly release that corresponds to the GeoServer you are running.

   Following the Community Modules link and download wps-download-netcdf zip archive.

   • 3.0-SNAPSHOT example: geoserver-3.0-SNAPSHOT-wps-download-netcdf-plugin.zip

   The website lists active nightly builds to provide feedback to developers, you may also browse for earlier branches.

5. Extract all the contents of the archives into the WEB-INF/lib directory of the GeoServer installation.

6. Restart GeoServer

Module description¶

This module adds further capabilities to the Raw data download processes Raw Data Download process of the WPS Download extension, by supporting dimension-aware filtering and NetCDF output. It enables users to download spatio-temporal grid coverages (such as climate or remote sensing data, for example) in NetCDF format, while filtering the data based on specific dimension values—like time, elevation, or other custom-defined dimensions. The filter is applied directly to the multidimensional data source. For example, in the case of an ImageMosaic, it targets the mosaic index to select multiple matching slices, which are then combined into the final NetCDF output file.

Relevant parameters of the Raw Data Download process:

1. layerName - name of the raster layer that has enabled dimensions (i.e. time, elevation)

2. filter - a filter containing subsetting on the attributes associated to the enabled dimensions

3. outputFormat - The mimeType of the requested output: application/x-netcdf or application/x-netcdf4 (if NetCDF-4 is enabled)

<ows:Identifier>gs:Download</ows:Identifier>
<wps:DataInputs>
  <wps:Input>
    <ows:Identifier>layerName</ows:Identifier>
    <wps:Data>
      <wps:LiteralData>it.geosolutions:watertemperature</wps:LiteralData>
    </wps:Data>
  </wps:Input>
  <wps:Input>
    <ows:Identifier>filter</ows:Identifier>
    <wps:Data>
      <wps:ComplexData mimeType="text/plain; subtype=cql"><![CDATA[ingestion >= '2013-09-11T00:00:00.000Z' and ingestion <= '2013-09-12T00:00:00.000Z' and elevation=0]]></wps:ComplexData>
    </wps:Data>
  </wps:Input>
  <wps:Input>
    <ows:Identifier>outputFormat</ows:Identifier>
    <wps:Data>
      <wps:LiteralData>application/x-netcdf</wps:LiteralData>
    </wps:Data>
  </wps:Input>
</wps:DataInputs>

Writing parameters¶

By default, the Settings configured in the NetCDF Output Settings of the layer (i.e. DataPacking, Compression level, Chunk Shuffling, variable names) are as Default writing parameters. Optionally, they can be overridden via explicit writeParameters input.

The writeParameters input element of a process execution allows to specify parameters to be applied by the outputFormat encoder when producing the output file. Writing parameters are listed as multiple <dwn:Parameter key="writingParameterName">value</dwn:Parameter> within a <dwn:Parameters> parent element. See the below xml containing full syntax of a valid example for NetCDF output format:

<wps:Input>
  <ows:Identifier>writeParameters</ows:Identifier>
    <wps:Data>
       <wps:ComplexData xmlns:dwn="http://geoserver.org/wps/download">
         <dwn:Parameters>
           <dwn:Parameter key="compression">5</dwn:Parameter>
           <dwn:Parameter key="shuffle">true</dwn:Parameter>
           <dwn:Parameter key="dataPacking">SHORT</dwn:Parameter>
           <dwn:Parameter key="variableName">air_temperature</dwn:Parameter>
           <dwn:Parameter key="uom">K</dwn:Parameter>
           <dwn:Parameter key="copyGlobalAttributes">true</dwn:Parameter>
           <dwn:Parameter key="copyVariableAttributes">true</dwn:Parameter>
         </dwn:Parameters>
       </wps:ComplexData>
    </wps:Data>
</wps:Input>

Note that the Shuffle and Compression parameters take effect only when the NetCDF-4 encoding is requested (using the application/x-netcdf4 MIME type).