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changes.mady.by.user Alex Minett

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Code Block
xml
xml
titlesample of Grids.xml
<?xml version="1.0" encoding="UTF-8"?>
<grids ...........>
  	<regular locationId="Landsat-gridGridName">
    <rows>256<		<rows>651</rows>
    <columns>256</columns>
    <geoDatum>Landat-grid</geoDatum>
    <firstCellCenter>
      <x>1250</x>
		<columns>1701</columns>
		<geostationarySatelliteView>
			<centralMeridian>0.0</centralMeridian>
		</geostationarySatelliteView>
		<firstCellCenter>
			<!-- First x must be -COFF*2**16/CFAC, first y must be (NR-LOFF)*2**16/LFAC as found in the HDF5 files
			      <y>-1250</y>
      <z>0</z>
    </firstCellCenter>
    <xCellSize>2500</xCellSize>
    <yCellSize>2500</yCellSize>
  </regular>
</grids>
Cell sizes must be 2**16/CFAC and 2**16/LFAC -->
			<x>-1.4796</x>
			<y>8.6854</y>
		</firstCellCenter>
		<xCellSize>0.00480387</xCellSize>
		<yCellSize>0.00480387</yCellSize>
</grids>

Description of the coordinate system:

  • The Landsat files contain a set of attributes, of which COFF, LOFF, CFAC and LFAC are the most important ones, as they can be used to determine the coordinate system.
  • According to the document http://www.eumetsat.int/groups/cps/documents/document/pdf_cgms_03.pdf, the image coordinates have to be converted to intermediate coordinates x and y that in turn can be converted into longitude and latitude.
  • For the Delft-FEWS configuration we need the extremes for x and y (as the satellite image is a rectangle in these coordinates).
  • The firstCellCenter's x and y need to be computed

Example Files

See attached files