[eml-dev] [Bug 2125] New: - Cannot define SOM map projection in spatialRaster element of EML2.0.1

[bugzilla-daemon@ecoinformatics.org]

http://bugzilla.ecoinformatics.org/show_bug.cgi?id=2125

           Summary: Cannot define SOM map projection in spatialRaster
                    element of EML2.0.1
           Product: EML
           Version: 2.0.1
          Platform: All
        OS/Version: All
            Status: NEW
          Severity: normal
          Priority: P2
         Component: eml - general bugs
        AssignedTo: jones at nceas.ucsb.edu
        ReportedBy: servilla at lternet.edu
         QAContact: eml-dev at ecoinformatics.org


I am having trouble defining the Space Oblique Mercator map projection
in the spatialRaster subtree of EML.  The problem is unique to the SOM
(any oblique map projection, for that matter) projection - the SOM does
not use a prime meridian in the usual sense (i.e., it is fixed to the
flight path of the Landsat satellite, not a geographic coordinate system).
Since EML requires the primeMeridian-longitude and unit-name attributes
to be strictly defined, the document will not validate.  Is there a
recommendation from the EML community for how to deal with this issue,
perhaps making the aforementioned attributes optional?

I have included below an example of how I would define this projection.

Notes:
1. The SOM projection does not appear to be common in the remote
sensing world other than EOSAT/Landsat/IRS formats.  Unfortunately, we have
much data in this projection.
2. FGDC has a separate element for this projection in their schema.
Actually, FGDC has a separate element for each major projection definition.

<spatialReference>
    <horizCoordSysDef name="SOM">
        <projCoordSys>
            <geogCoordSys>
                <datum/>
                <spheroid name="International_1909" semiAxisMajor="6378388" 
denomFlatRatio="0.996633"/>
                <primeMeridian longitude=""/>
                <unit name="">
            </geogCoordSys>
            <projection>
                <parameter name="Landsat_Number" value="5"/>
                <parameter name="Landsat_Path" value="36"/>
                <parameter name="False_Easting" value="0"/>
                <parameter name="False_Northing" value="0"/>
                <unit name="meter">
            </projection>
        </projCoordSys>
    </horizCoordSysDef>
</spatialReference>