Earthdata Forum

Hi, I am trying to run seadas-10 l2gen on VIIRS-SNPP L1A data. This command works all right with previous l2gen versions, like 9.6, 9.7, now it returns errors. The command is run from a container, aiming to produce L1C files (L2 with all gains 1). The resulting command was:
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[b]l2gen ifile="/workdir/SNPP_VIIRS.20230613T183000.L1A.nc" geofile="/workdir/SNPP_VIIRS.20230613T183000.GEO" ofile="/tmp/tmpfiles_cqnygz_2/SNPP_VIIRS.20230613T183000.L1C" l2prod="rhot_nnn polcor_nnn sena senz sola solz latitude
longitude" gain="1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0" atmocor=0 aer_opt=-99 brdf_opt=0[/b]
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Loading default parameters from /opt/seadas/ocssw/share/common/msl12_defaults.par
sh: 1: getfattr: not found
Input file /workdir/SNPP_VIIRS.20230613T183000.L1A.nc is VIIRS NPP L1A NetCDF4.

Error output:
============

[b]Reading Thuillier_F0.dat
openl1 - Unknown L1 input file format specifier: 34
-E- l2gen: Error opening /workdir/SNPP_VIIRS.20230613T183000.L1A.nc for reading.
exiting l2gen
Command exited with non-zero status 1[/b]
======================
Thank you for help.
Andrei

To simplify the inner workings of l2gen for VIIRS we no longer support giving l2gen a VIIRS L1A file as the ifile. The ifile needs to be an L1B. Use "calibrate_viirs" to make an L1B from the L1A.
don

Many thanks, very helpful!
Cheers,
Andrei

andrei_mitrich wrote:
> "Reading Thuillier_F0.dat
openl1 - Unknown L1 input file format specifier: 34
-E- l2gen: Error opening /workdir/SNPP_VIIRS.20230613T183000.L1A.nc for reading."

It's definitely a change in the workflow for SeaDAS 10. It seems that the newer OCSSW updates now strictly require the L1B conversion via calibrate_viirs before running l2gen, whereas older versions were a bit more flexible with the input types.