4.6. Processing from command line

Since the ICOL+ processor makes use of the BEAM graph processing framework, it can be used also as a command line tool outside BEAM-VISAT. The graph processing is invoked by the command

${BEAM-INSTALL-DIR}/bin/gpt

To obtain general help on the graph processing, use the command

${BEAM-INSTALL-DIR}/bin/gpt -h

Specific help on the ICOL+ processor (MERIS or LANDSAT TM), can be obtained with

${BEAM-INSTALL-DIR}/bin/gpt -h icol.Meris
${BEAM-INSTALL-DIR}/bin/gpt -h icol.ThematicMapper
${BEAM-INSTALL-DIR}/bin/gpt -h icol.EnhancedThematicMapper

In this case, information on the usage and a list of all available parameters are given. (seeFigure 4.9).

Figure 4.9. ICOL+ command line processing

If MERIS N1 products shall be written as output result a graph xml file has to be created. This xml file should concatenate the icol.Meris operator and the Meris.N1Patcher operator. A possible graph xml file would look like the following. For demonstration purpose only the necessary parameter have been set.

            
            <graph id="N1Icol">
                <version>1.0</version>
                <node id="merisIcol">
                    <operator>icol.Meris</operator>
                    <sources>
                        <sourceProduct>${n1Product}</sourceProduct>
                    </sources>

                </node>
                <node id="n1Writer">
                    <operator>Meris.N1Patcher</operator>
                    <sources>
                        <n1>${n1Product}</n1>
                        <input>merisIcol</input>
                    </sources>
                    <parameters>
                        <patchedFile>${n1TargetFile}</patchedFile>
                    </parameters>
                </node>
            </graph>

This graph can be invoked by the following call on the command line:

            
               gpt <graph-file.xml> -Pn1TargetFile=<path-to-target-file> -Sn1Product=<path-to-source-file>