I'm trying to convert pixel coordinates of a TIFF file into longitude and latitude ones. The image is from a grib product of a geostationary satellite and I want to georeference it.

I'm reading this doc http://2014.cgms-info.org/documents/cgms-lrit-hrit-global-specification-%28v2-8-of-30-oct-2013%29.pdf - Section 4.4, page 29.

Formula in page 29 returns small values from 0.0 to about 1.6. They are the so called "intermediate values", now I need to scale it. In page 32 there is the scaling function for that, but I don't know the coefficients declared in that...

Does someone know the correct way?

  • Page 32 says that you read the coefficients from the image's navigation record (page 17). – mkennedy Feb 5 '15 at 18:18
  • Are you sure that the grib file does not contain coordinate info in separate bands or metadata? – AndreJ Feb 5 '15 at 18:23
  • GRIB format doesn't make sense to me as a TIFF file. GRIB is a message oriented format, quite unlike TIFF. Can you add the gdalinfo output for the file you're working on to the question? Where did the data come from originally? – BradHards Feb 5 '15 at 22:20
  • Shouldn't this question mention/explain some terms CGMS, grib, LRIT/HRIT? I've never heard of any of them. – Martin F Feb 8 '15 at 6:46
  • You can find COFF, LOFF, CFAC and LFAC in the files metadata, accessible with gdalinfo. At least LSASAF data has it there. – AndreJ May 14 '16 at 18:51

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