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Blank Rrs L2 VIIRS Bands

Posted: Wed Aug 04, 2021 5:05 pm America/New_York
by kelseaedwing
Hi,

I processed a VIIRS L1A to L2 and need the rhos and Rrs products. When I open the Rrs band products in SeaDAS, however, they are blank and the rhos products are in stripes. Did I process this wrong or is this a software thing?

Thanks!

Re: Blank Rrs L2 VIIRS Bands

Posted: Thu Aug 05, 2021 10:22 am America/New_York
by OB SeaDAS - xuanyang02
It will be helpful that you share with us what VIIRS L1 file you used to do l2gen, assuming you have the corresponding geo file.

Could you also please share the screenshot of striped rhos product?

Re: Blank Rrs L2 VIIRS Bands

Posted: Thu Aug 05, 2021 10:44 am America/New_York
by kelseaedwing
Hi,

I can't attach the files because they are netCDFs, but the VIIRS file name I'm using is V2021201083000.L2_JPSS1_OC.nc and its geofile is V2021201083000.GEO-M_JPSS1.nc. The link to the files is here: https://oceandata.sci.gsfc.nasa.gov/VII ... /2021/201/

Attached are screenshots of the striped VIIRS rhos. One is a close-up of rhos_667 and the other is an image of the whole dataset of rhos_667.

Thanks,
Kelsea

Re: Blank Rrs L2 VIIRS Bands

Posted: Fri Aug 06, 2021 7:32 am America/New_York
by OB.DAAC - SeanBailey
That scene is at night, so no valid reflective solar band data to be had.

Sean

Re: Blank Rrs L2 VIIRS Bands

Posted: Fri Aug 06, 2021 11:52 am America/New_York
by kelseaedwing
Hi Sean,

The matching data on the VIIRS L1 & L2 data download site shows an image taken during the day. And the timestamp of the geofile and L1A image is 16:09 and 16:00 respectively (although this might not be the time the image was taken).

Thanks,
Kelsea

Re: Blank Rrs L2 VIIRS Bands

Posted: Fri Aug 06, 2021 12:27 pm America/New_York
by OB SeaDAS - xuanyang02
Kelsea,

The time 16:09 and 16:00 is the time the files were last modified.

If you open V2021201083000.L1A_JPSS1.nc in SeaDAS and click Global_Attributes, you can see the day_night_flag value is Night.
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Re: Blank Rrs L2 VIIRS Bands

Posted: Fri Aug 06, 2021 2:00 pm America/New_York
by kelseaedwing
Sean,

Oh gosh, I was not paying attention and matched the VIIRS SNPP file names on the L1 & L2 download portal to the file names of the VIIRS JPSS in the archive. I'll download the correct daytime image.

Thanks for the help,
Kelsea