How to create VIIRS L1A from L0?

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liamgumley
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How to create VIIRS L1A from L0?

by liamgumley » Wed Jan 08, 2020 2:02 pm America/New_York

SeaDAS gurus,

Does SeaDAS 7.5 have the ability to create VIIRS L1A from L0 PDS files? Specifically, the VIIRS L0 PDS files one can create from direct broadcast data? If so, which binary is used and what is the calling syntax?

Thanks,
Liam.

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OB.DAAC - SeanBailey
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How to create VIIRS L1A from L0?

by OB.DAAC - SeanBailey » Wed Jan 08, 2020 5:14 pm America/New_York

No, it doesn't.  We haven't distributed the l1agen_viirs binary with SeaDAS.  I suppose we *could*, but to date there has been zero interest in it.  In the 7 years since we added support for VIIRS, you're the first to ask about L0 processing...

Sean

smasse
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Re: How to create VIIRS L1A from L0?

by smasse » Sat Oct 16, 2021 7:32 pm America/New_York

Hello,

I have also an interest in VIIRS L0 to L1A generation in order to generate SST and OC products as quick as possible from SNPP and JPSS-1 as we currently do for Aqua and Terra.

Serge Masse, Global Imaging, Inc.

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Re: How to create VIIRS L1A from L0?

by OB.DAAC - SeanBailey » Mon Oct 18, 2021 11:17 am America/New_York

The VIIRS L1A products we distribute are available as soon as we receive the L0 data. The L0 data are in orbit-based (nominally 90 minutes) which are replaced by 2-hour PDS files. The orbit based files are available with a sub-3hour latency and the 2-hour replay (and the official archive product) with a nominal 7 hour latency from data collection. We do not distribute the PDS files, but even if we did, they would be available at the same time as the 6 minute L1A files they produce. So, there is no need for the l1agen_viirs code to be run by users, just grab the L1A files that we make available.

Regards,
Sean

smasse
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Re: How to create VIIRS L1A from L0?

by smasse » Fri Oct 22, 2021 11:12 pm America/New_York

Thanks Sean,

I have a customer who wishes to process SNPP and JPSS-1 DB in near real time. Their latency requirement is around 45 minutes. Is there a way to do this?

In any case I would also like to test the VIIRS chain, where can I get the SNPP and VIIRS L1A data?

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Re: How to create VIIRS L1A from L0?

by OB.DAAC - SeanBailey » Mon Oct 25, 2021 7:04 am America/New_York

I don't know. Probably. Ask the direct broadcast folks:

https://directreadout.sci.gsfc.nasa.gov/

The L1A VIIRS data (but not the L0) are available from our data distribution site:
https://oceandata.sci.gsfc.nasa.gov

Regards,
Sean

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