Seadas GEO.hdf

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arnabp893
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Seadas GEO.hdf

by arnabp893 » Mon Aug 01, 2022 11:58 am America/New_York

I am having few problems with seadas.Firstly, I am having trouble with putting my own lat/lon data. I have tried both the approach from pin manager to provide .txt file and and adding csv file from export>pixel extraction. Both showing the same error of 'error occurred while reading file; Neither lat/lon nor geometry column provided. I have proviced the file this format attached with the question.
Second, now the Geo.hdf file is directly available in the website. But when i opened the ocssw>modis L1A, I couldn't be able to put the geo file as there was no slot. So, I went back to modis_geo (Which doesn't make any sense) for the file to retrieve the file from there. but it showed this
"Error! dump_metadata failed.
Can't find input file ...GEO.hdf"
I am learning seadas and started as a newbi. So these questions are appearing while working with the data.
Thank you in advance
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OB SeaDAS - knowles
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Re: Seadas GEO.hdf

by OB SeaDAS - knowles » Mon Aug 01, 2022 2:25 pm America/New_York

For the answer to your first question:
Your csv file used to import the lat/lon values into the Pixel Extraction Tool needs to be a very precisely formatted text file.

For example your csv file could be as follows (where "\t" denotes a tab character, and there are no other hidden characters)

Code: Select all

Name\tLat\tLon
1\t-74.06455993652344\t39.430782318115234
2\t-73.27050018310547\t38.75559616088867
3\t-72.27462768554688\t38.29384994506836
Note: you do need the header line.
Note: "\t" needs to be a tab character and not merely the characters "\t"
Also note that you could optionally add a fourth column called "DateTime" of the format "2009-06-07T08:27:11" if you wish to include time criteria.

OB SeaDAS - xuanyang02
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Re: Seadas GEO.hdf

by OB SeaDAS - xuanyang02 » Mon Aug 01, 2022 2:36 pm America/New_York

For the 2nd question, you do not need a modis_GEO file to do modis_L1A.

modis_L1A: L0 -> L1A https://seadas.gsfc.nasa.gov/help-8.2.0/processors/ProcessModis_L1A.html

modis_L1B: L1A + GEO -> L1B https://seadas.gsfc.nasa.gov/help-8.2.0/processors/ProcessModis_L1B.html

Are you using SeaDAS-8.2.0 and ocssw V2022.0?

arnabp893
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Re: Seadas GEO.hdf

by arnabp893 » Mon Aug 01, 2022 4:56 pm America/New_York

Yes SeaDAS is 8.2.0 and ocssw is V2022.0.
I think I need to update as I have no option to put my geofile given in the box. Thank you
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arnabp893
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Re: Seadas GEO.hdf

by arnabp893 » Mon Aug 01, 2022 4:59 pm America/New_York

Unfortunately, I have put the L2 file in the screenshot but L1A.LAC is also showing the same result

OB SeaDAS - xuanyang02
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Re: Seadas GEO.hdf

by OB SeaDAS - xuanyang02 » Tue Aug 02, 2022 12:23 pm America/New_York

modis_L1B takes an L1A file, so you can't choose an L2 file for input.

I have AQUA_MODIS.20101010T180500.L1A.hdf as the input file, and I have downloaded AQUA_MODIS.20101010T180501.GEO.hdf in the same directory. modis_L1B GUI does not give you the option to input GEO file in this case, for it found AQUA_MODIS.20101010T180501.GEO.hdf as the GEO file. You can go ahead click run, and modis_L1B will proceed to create the L1B file.

arnabp893
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Re: Seadas GEO.hdf

by arnabp893 » Thu Aug 04, 2022 2:22 pm America/New_York

I don't understand that when I am selecting the L1A file it is not allowing me to run. Do I have to convert it to some other format?
I am keeping both the files in the same directory.
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OB.DAAC - SeanBailey
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Re: Seadas GEO.hdf

by OB.DAAC - SeanBailey » Thu Aug 04, 2022 9:59 pm America/New_York

Do not have directories with spaces in the name. Rename "Modis Data" to not include a space and it should work.

Sean

arnabp893
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Re: Seadas GEO.hdf

by arnabp893 » Fri Aug 05, 2022 1:54 pm America/New_York

Thats a very minute detail I was missing. THank you sir. It is working fine now.

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