Forum

Dear Forum experts, We are processing L1A data for MODIS, VIIRSN and VIIRSJ1 with SEADAS l2gen, to L1C, which effectively means L2 with all gains set to 1 for use in processing with the POLYMER atmos correction that has its own SVC gains. We have noticed that in NASA reprocessings (say, r2018, r2022...

Hi, I do not know the answer but also would be glad to hear any updates on this. I believe initial degradation started being observed some time around 2018-2019 and was getting worse with the time? I'd like to take a liberty to add couple of related questions in addition to the initial question from...

Many thanks, very helpful!
Cheers,
Andrei

Test test Hi, I find posting without text formatting (BBCode) makes post reading difficult. I cannot find out how to turn this feature on; instead I see: Whether you can actually use BBCode in your posts on the forum is determined by the administrator which only leaves me with one option: kindly as...

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: -------------------------...

Hi, For few NASA sensors, we are processing L1A data to L1C, using SEADAS tools modis_GEO, modis_L1B and l2gen. I have noticed, our processing tool including those 3 SEADAS tools fails if input modis L1A files do not have write permission. When I added it, processing succeeded BUT! ... input L1A got...

Hi, I am trying to extract matchups for Rrs for few sensors against in-situ MOBY data. Some time ago, maybe a year, all the tools worked for all sensors I tried: MODISA, MERIS, SEAWIFS, VIIRS(N/J1/J2). After some changes on NASA site, first stopped previously working commands with `_L2_oc` pattern; ...

Hi Sean, Thank you for the reply and explanations. I am still not quite happy with the answer. That case in the very beginning of the satellite life , Feb 18, 2012, was indeed an extreme case: I checked - we neither could produce L2 files from those L1A files though we do have those L1A files. How a...

Hi, When renaming to the latest convention SNPP VIIRS L1A files in our local storage, downloaded few years ago, still in format V2012049033600.L1A_SNPP.nc, I have noticed some of our local files could not be found at the NASA storage: https://oceandata.sci.gsfc.nasa.gov/directdataaccess . We always ...

Hi, We have downloaded some time ago VIIRS SNPP L1A data, without last few years. Now I can see that file name format changed: instead of V2019164192400.L1A_SNPP, we see something like SNPP_VIIRS.20190613T192400.L1A.nc. The file content however, if we compare the same granules, did not change, at le...