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by simkins » Thu Oct 19, 2017 11:30 am America/New_York
I'm currently unable to recreate the quasi true color image located on the Ocean Color Browse website. l1brsgen allows me to get pretty close, but the bowtie effect ruins the image. l1mapgen removes most of the bowtie effect, but the image isn't as clear as I would like and I can't seem to find the right projection. I'll provide a reproducible workflow and would really appreciate any help on this matter. I apologize if something similar had been posted before, I was unable to find anything.
Command Line Syntax: #Using l1brsgen and then R to convert l1brsgen_example.hdf to l1brsgen_example.png l1brsgen ifile=V2017286183600.L1A_SNPP.nc geofile=V2017286183600.GEO-M_SNPP.nc ofile=l1brsgen_example.hdf subsamp=1 atmocor=1 resolution=1000 oformat=1 oformat_depth=24bit par=pars.txt
The TC browse images on the L1/2 browser are indeed created using l1brsgen. For VIIRS, the defaults for l1brsgen are the full image with no atmospheric correction applied (well, no Rayliegh correction), however, the images on the browser are subsampled and apply a Rayleigh correction...there's an added bit of voodoo, in that to make sure the subsampling skips the bowtie deleted pixels, we start on the third line :wink: Add these two parameters to your l1brsgen call: subsamp=8 sline=3 atmocor=1