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This one required a bit of sleuthing...and contacting the developer who originally provided the code used in l2gen. It has been determine that this change went into the code base circa 2006, when updates were made going from version 2 to version 3 of QAA. The current code is version 6. As to exactly...

For my case, the 'Get ancillary' did not download anc_aerosol files (I checked the ''/Users/*****/SeaDAS/ocssw/var/anc/2024/122/"). Did I miss something when I used the l2gen?? No, you didn't. The getanc code has not been updated to include the anc_aerosol files. These files are currently only...

It appears that ENVI is not applying the scale_factor and add_offset parameters to convert the scaled integers stored in the L2 file into geophysical values: (ncdump -h <PACE AOP file>|grep Rrs) short Rrs(number_of_lines, pixels_per_line, wavelength_3d) ; Rrs:long_name = "Remote sensing reflect...

Yes, that is the process. The getanc call goes before l2gen to identify (and download) the ancillary inputs to the l2gen process. BTW, calibrate_viirs can output three different files, thus in place of ofile it uses l1bfile_[img,mod,dnb]. BTW, the calibrate_viirs code includes the bits of the geoloc...

Yes, l2gen can take a VIIRS L1A file as input (performing the calibration on-the-fly), but the VIIRS geolocation and calibration programs share code, so if you are unable to process the geoocation, you will likely have issues calibrating - either with calibrate_viirs or l2gen.

Sean

Julien, The issue actually started on Oct 5th, and is a ground station issue. Increased solar activity during that time interfered with the ground stations' spacecraft tracking causing data loss during downlinks. The data are likely not recoverable: https://landweb.modaps.eosdis.nasa.gov/displayissu...

At Level 2, pixels identified as possibly having significant coccolithophore concentration are flagged. These pixels are excluded when the data are binned to Level 3: https://oceancolor.gsfc.nasa.gov/resources/atbd/ocl2flags/ The coccolithophore flag is based on some pretty old work: https://doi.org...

The most common reason for differences in l2gen output is differences in the ancillary sources used. Make sure to use the getanc utility to identify and download the required ancillary inputs

Sean

The sites are up and functional. If you are still unable to access them you can send an email to connection_problems@oceancolor.gsfc.nasa.gov with information describing your issue, your IP address and the time you attempted the connection.

Sean

From NOAA operations: > All PDA OPS subscriptions for all S-NPP science products were disabled at > 14:00z on September 25, 2024. High Rate Data (HRD) was also disabled at > 15:16:44z on September 25, 2024. These will remain disabled until further > notice. > Update #1: Engineering was able to confi...