vicarious gain coefficients to rhot

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akashashapure
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vicarious gain coefficients to rhot

by akashashapure » Tue Dec 06, 2022 11:09 am America/New_York

I am using L2gen to find OLI matchups. I am wondering if you apply any vicarious gain coefficients to the output top of the atmosphere reflectance, or is it the actual recorded value of OLI instead?


Thanks!
Akash Ashapure
akash.ashapure@nasa.gov

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OB.DAAC - SeanBailey
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Re: vicarious gain coefficients to rhot

by OB.DAAC - SeanBailey » Wed Dec 07, 2022 9:59 am America/New_York

For Landsat8/OLI, yes:
grep ^gain $OCDATAROOT/oli/l8/msl12_defaults.par
gain=[1.0111,1.0101,1.0070,1.0098,1.00,1.00,1.00]

The configuration for L9 was just copied from L8, so by default it has the same gains...probably shouldn't though.

If you want the values "as is", when running l2gen,

set: gain=[1.00,1.00,1.00,1.00,1.00,1.00,1.00]

AND
either comment out these lines in the $OCDATAROOT/oli/msl12_filter.dat file:
ltmean, 1, 7, 7, 1
ltmean, 2, 7, 7, 1
ltmean, 3, 7, 7, 1
ltmean, 4, 7, 7, 1
ltmean, 5, 7, 7, 1
ltmean, 6, 7, 7, 1
ltmean, 7, 7, 7, 1

OR define a blank file to pass to l2gen as the filter_file

Sean

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