Earthdata Forum

Hello,
     I have been processing L1 to L2 for MODIS (250 m), OLCI, OLI, and MSI. I first extract the region of interest from L1 image then use l2gen to get L2 images. FInally I reproject the L2 images using gpt.
   I was wondering if I can reproject L1 images first and the use l2gen to get L2 images.  Is that better in any way?
Thanks.
Amita

No, you cannot reproject L1 images and then run l2gen.  All the science processors within the OCSSW menu are strict science data processors with specific input file types and formats, tracking through specific science data levels.  The other more generic GUI/GPT tools such as Reproject, Subset, Collocate, etc. are not part of OCSSW.  So you cannot use the output of the non-OCSSW tools as input to the OCSSW software.

Note that there are "reproject" tools within OCSSW.  This would involve taking the level-2 file and running it through l2bin and then through l3mapgen.

Danny