Multiple MODIS L2 file processing in Seadas

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bijaylaxmi
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Multiple MODIS L2 file processing in Seadas

by bijaylaxmi » Tue May 31, 2022 4:15 pm America/New_York

Hello,
I am new to Seadas and I have 100s of MODIS L1 files to generate L2 products.
It would take a long time to run l2gen one by one for each file in the GUI.
I would like to know if there is a way to run all the files together.
Thanks,
Bijaylaxmi

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OB SeaDAS - xuanyang02
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Re: Multiple MODIS L2 file processing in Seadas

by OB SeaDAS - xuanyang02 » Wed Jun 01, 2022 10:30 am America/New_York

Yes, multilevel_processor can process multiple files when you choose ifilelist.txt as your ifile, and your ifilelist.txt contains the absolute path of your L1 files like this

/Users/*/Scenes/Aqua/A2010283180500.L1A_LAC
/Users/*/Scenes/Aqua/A2010290181000.L1A_LAC

Here is the help page for multilevel_processor -- https://seadas.gsfc.nasa.gov/help-8.2.0/processors/ProcessMultilevel_processor.html

bijaylaxmi
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Re: Multiple MODIS L2 file processing in Seadas

by bijaylaxmi » Wed Jun 01, 2022 1:57 pm America/New_York

Thank you xuanyang02 for the reply.
I tried to use multilevel-processor. I came across some issues.
1. While uploading the file, a warning appears that the file does not exist. I followed the format you have mentioned to create a iflielist.txt file.
2. Does the multilevel-processor download the ancillary files for all the input files?

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Re: Multiple MODIS L2 file processing in Seadas

by OB SeaDAS - xuanyang02 » Wed Jun 01, 2022 2:06 pm America/New_York

1. Please show me the content of your ifilelist.txt and make sure the files listed in your ifilelist.txt do exist

2. Check the checkbox of use_ancillary in the Main Options section, so l2gen will download and use the ancillary files for all the input files

bijaylaxmi
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Re: Multiple MODIS L2 file processing in Seadas

by bijaylaxmi » Wed Jun 01, 2022 2:46 pm America/New_York

Hello xuanyang02
Here is the content of my ifilelist.txt. For test run, I have added only 2 files.
/Users/gulf/Documents/A2016299190000.L1A_LAC
/Users/gulf/Documents/A2016320191500.L1A_LAC
The files listed are in the Documents. I listed the full path of the files in excel and saved as tab delimited text format.

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Re: Multiple MODIS L2 file processing in Seadas

by OB SeaDAS - xuanyang02 » Thu Jun 02, 2022 11:04 am America/New_York

Sorry that I forgot to mention that you might want to use a plain text editor like vi or emacs to edit the ifilelist.txt. Multilevel_processor is not smart enough to read anything other than plain text in ifilelist.txt.

bijaylaxmi
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Re: Multiple MODIS L2 file processing in Seadas

by bijaylaxmi » Thu Jun 02, 2022 2:11 pm America/New_York

Hello xuanyang02,
Thank you for the solution. I can input the files now and can run the multilevel_processor.

I would like to know if multilevel processor can run 250m/500m resolution.
Also, I would like to know if l1aextract works on multilevel processor.
Because, I tried to reduce resolution in l2gen miscellaneous and also I tried to subset the files in l1aextract. Both the time the execution failed. Without these 2 operations, everything runs very smoothly.

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Re: Multiple MODIS L2 file processing in Seadas

by OB SeaDAS - xuanyang02 » Mon Jun 06, 2022 3:25 pm America/New_York

l1aextract should work as a processor in multilevel_processor's processor chain. l2gen with resolution as an mlp processor is a little tricky for OCSSW V2022.0. We know V2022.0 has issues for modis_L1B to produce L1B HKM/QKM files with correct names, which will fail l2gen with resolution when it could not find correct HKM/QKM files. So you need R2022.4 for multilevel_processor to work properly with l2gen with resolution.

1. SeaDAS-OCSSW -> Configure OCSSW Location, set OCSSW ROOT to /Users/gulf/ocssw-R2022.4

2. SeaDAS-OCSSW -> Install/Update OC Processors, Choose R2022.4 for OCSSW Tag, Check modisa, and Run

3.SeaDAS-OCSSW -> Multilevel_processor, paste the following content in the Parfile area and Run.

[main]
ifile=/Users/gulf/Document/A2005335192500.L1A_LAC
use_ancillary=1
overwrite=1
odir=/Users/gulf/Documents

[l1aextract]
SWlon=-92.5
SWlat=26
NElon=-87.5
NElat=31

[l2gen]
resolution=250

Sometimes, you need to quit and restart SeaDAS for multilevel_processor to work properly

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