Plate Carree Projection: No 'Coordinate Reference System' selected

[treble]

I am trying to reproject a netCDF file with Plate Carree projection, with the Mosaicking tool (so I can use the output to create a Google Earth kmz file down the road). However, when I click 'Run' I get the error "No 'Coordinate Reference System' selected". I have WGS 1984 selected as the Geodetic datum... See screenshot below.

Tried it with SeaDAS 8.4.1 and 9.1.0.

Screenshot 2024-11-01 at 10.48.56 AM.png (229.27 KiB) Not viewed yet

[OB SeaDAS - xuanyang02]

Could you please share the name of your file, so we can replicate the issue?

[treble]

I have tried different ones. Like this one for example: https://oceandata.sci.gsfc.nasa.gov/getfile/AQUA_MODIS.20241031.L3m.DAY.CHL.chlor_a.4km.NRT.nc

[treble]

Just a follow up, if I export the Mosaicking parameters to an xml file, the <crs> part is indeed missing for Plate Carree. See below 2 examples. First selecting Plate Carree, second selecting Geographic Lat/Lon (WGS 84).

Example plate carree:

Code: Select all

<parameters>
    <variables>
        <variable>
            <name>sla</name>
            <expression>sla</expression>
        </variable>
    </variables>
    <combine>OR</combine>
    <orthorectify>false</orthorectify>
    <elevationModelName>Copernicus 90m Global DEM</elevationModelName>
    <resampling>Nearest</resampling>
    <westBound>-161.50761632653058</westBound>
    <northBound>12.731988571428602</northBound>
    <eastBound>-101.14597020408152</eastBound>
    <southBound>-24.670787959183684</southBound>
    <pixelSizeX>0.05</pixelSizeX>
    <pixelSizeY>0.05</pixelSizeY>
</parameters>

Example Geographic Lat Lon:

Code: Select all

<parameters>
    <variables>
        <variable>
            <name>sla</name>
            <expression>sla</expression>
        </variable>
    </variables>
    <combine>OR</combine>
    <crs>GEOGCS[&quot;WGS84(DD)&quot;, 
      DATUM[&quot;WGS84&quot;, 
        SPHEROID[&quot;WGS84&quot;, 6378137.0, 298.257223563]], 
      PRIMEM[&quot;Greenwich&quot;, 0.0], 
      UNIT[&quot;degree&quot;, 0.017453292519943295], 
      AXIS[&quot;Geodetic longitude&quot;, EAST], 
      AXIS[&quot;Geodetic latitude&quot;, NORTH], 
      AUTHORITY[&quot;EPSG&quot;,&quot;4326&quot;]]</crs>
    <orthorectify>false</orthorectify>
    <elevationModelName>Copernicus 90m Global DEM</elevationModelName>
    <resampling>Nearest</resampling>
    <westBound>-161.50761632653058</westBound>
    <northBound>12.731988571428602</northBound>
    <eastBound>-101.14597020408152</eastBound>
    <southBound>-24.670787959183684</southBound>
    <pixelSizeX>0.05</pixelSizeX>
    <pixelSizeY>0.05</pixelSizeY>
</parameters>

[OB SeaDAS - knowles]

This appears to be a bug where the Mosaic tool isn't recognizing "Plate Carree". I tested some other coordinate systems and they work fine.

"Plate Carree" is actually exactly the same as calling the "Equidistant Cylindrical" projection with the "standard parallel 1 = 0.0". So use this:

eqc.png (116.85 KiB) Not viewed yet

For reference see - https://proj.org/en/9.5/operations/projections/eqc.html

[treble]

Thanks for the tip. Very helpful. I knew they were similar, but couldn't find out how to make the exactly the same. So many different projections...

FWIW, I also tried it with Snap 9.0.0, and got the same error, so it is not a SeaDAS specific thing.