CMR API response does not list all the Rrs band files

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OB ODPS - towens
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Re: CMR API response does not list all the Rrs band files

by OB ODPS - towens » Mon Oct 25, 2021 4:40 am America/New_York

For ocean color files, all versions have the same file names and the newer version overwrites the older on the archive. Currently, the only way to tell them apart is by checking the NetCDF global attributes for the pversion

A2021181.L3m_DAY_CHL_chlor_a_4km.nc
:pversion = "2018.1" ;

A2021182.L3m_DAY_CHL_chlor_a_4km.nc
:pversion = "2018.1QL" ;

When we reprocess the collections later this year, we will be changing the file names and adding an "NRT" to the QuickLook filenames.

For example, we have adopted this naming convention for our SST files:

AQUA_MODIS.20210929.L3m.DAY.SST.sst.4km.nc
AQUA_MODIS.20210930.L3m.DAY.SST.sst.4km.NRT.nc

Tommy

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earthengine_urs
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Re: CMR API response does not list all the Rrs band files

by earthengine_urs » Tue Oct 26, 2021 12:56 am America/New_York

Tommy,

So to revisit my other question, is it expected to not see in CMR some file names present on oceandata.sci.gsfc.nasa.go?

Currently https://cmr.earthdata.nasa.gov/search/g ... age_num=38 returns A2021181.L3m_DAY_CHL_chlor_a_4km.nc as the last entry, yet I see the next day's file, A2021182.L3m_DAY_CHL_chlor_a_4km.nc, on https://oceandata.sci.gsfc.nasa.gov/dir ... /2021/182/

Thanks,
Simon

OB ODPS - towens
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Re: CMR API response does not list all the Rrs band files

by OB ODPS - towens » Tue Oct 26, 2021 5:53 am America/New_York

There are two CMR collections of MODIS CHL data:

The NRT or QuickLook collection:
C1449861405-OB_DAAC

The Refined Collection:
C1442922862-OB_DAAC

You can find them by searching for "MODISA_L3m_CHL"

If you look at the top line of the page of the CMR results you link to, you will see:
https://cmr.earthdata.nasa.gov/search/concepts/C1442922862-OB_DAAC.html

That tells me that these results are from the Refined collection.

On OceanData, there is no Refined/NRT distinction:
https://oceandata.sci.gsfc.nasa.gov/directaccess/MODIS-Aqua/L3SMI/2021/182/

So yes, you will see NRT files listed there that do not appear in your CMR query of the Refined collection.

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