The SMOS Global Mapping Tool (GMT) is useful for plotting the SMOS data into a single global geographical map. The GMT is also able to visualise additional quantities derived from SMOS data (i.e. first Stokes parameter) and to filter data based on the quality flag available in the SMOS products. The tool requires a Linux operating system and the installation of the IDL virtual machine or a licensed version of IDL (v6.2 or above).
You can simply call the GMT from the command line specifying a configuration file to be used as the only argument. By setting the appropriate values in this configuration file, you will be able to select the parameters to be plotted according to the product type. You will also be able to specify the projection, map centre, filters, format of the output files, etc. Although just a single parameter will be visualised at a time (i.e. on one single geographic map), several parameters can be specified in the configuration file; in this case the tool will generate as many geographic maps as specified parameters. For that purpose, you would need to be acquainted with the various L1 and L2 SMOS products in order to define the appropriate configuration for the GMT.
The GMT configuration files themselves are based on a human-readable XML format, and thus they can be written or modified by hand through a regular text editor, or created by means of a specific XML tool.