Reprojection of MODIS products using SeaDAS 8.4.1 revealed discrepancies in the products generated using the GUI generation HO gpt. When confronted with an image spanning 180° of longitude, the product generated using gpt is missing a portion, whereas the product generated directly using the GUI does not.
The gpt code I use:
gpt ReprojectGraphEx01.xml -p ReprojectEx01.par -Pifile="!infile!" -Pofile="!outfile!"
ReprojectGraphEx01.xml is:
<graph id="ReprojectGeoLatLonGraph">
<version>1.0</version>
<node id="Read">
<operator>Read</operator>
<sources/>
<parameters class="com.bc.ceres.binding.dom.XppDomElement">
<file>${ifile}</file>
<formatName>SeaDAS-L2</formatName>
</parameters>
</node>
<node id="Reproject">
<operator>Reproject</operator>
<sources>
<sourceProduct refid="Read"/>
</sources>
<parameters class="com.bc.ceres.binding.dom.XppDomElement">
<wktFile/>
<crs>
GEOGCS["WGS84(DD)",
DATUM["WGS84",
SPHEROID["WGS84", 6378137.0, 298.257223563]],
PRIMEM["Greenwich", 0.0],
UNIT["degree", 0.017453292519943295],
AXIS["Geodetic longitude", EAST],
AXIS["Geodetic latitude", NORTH]]
</crs>
<resampling>${resampling}</resampling>
<orientation>0.0</orientation>
<pixelSizeX>${pixelSize}</pixelSizeX>
<pixelSizeY>${pixelSize}</pixelSizeY>
<orthorectify>false</orthorectify>
<noDataValue>NaN</noDataValue>
<includeTiePointGrids>true</includeTiePointGrids>
<addDeltaBands>false</addDeltaBands>
</parameters>
</node>
<node id="Write">
<operator>Write</operator>
<sources>
<sourceProduct refid="Reproject"/>
</sources>
<parameters class="com.bc.ceres.binding.dom.XppDomElement">
<file>${ofile}</file>
<formatName>NetCDF4-CF</formatName>
</parameters>
</node>
</graph>
ReprojectEx01.par is :
pixelSize=0.009
resampling=Nearest
The individual parameters I selected in the GUI interface are:
CRS:Custom CRS Projection:Geographic Lat/Lon (WGS 84)
Resolution: Easting ,Northing ,Orientation are default, Pixel SizeX and SizeY are 0.009
Resampling method:Nearest
No-data value : NAN
“Reproject tie-point grids” is checked.
computer operating system:Windows 11
seadas 8.4.1 reprojection of MODIS images using gpt found different products than those obtained directly using the GUI
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Re: seadas 8.4.1 reprojection of MODIS images using gpt found different products than those obtained directly using the
Unfortunately GPT doesn't seem to work on the current version of SeaDAS. We are looking in it for a future release. If you need to use gpt now, then you might try downloading SNAP. Also, regarding this question, you might try asking on the SNAP forum as a lot of SNAP users work with gpt. (https://forum.step.esa.int/)