Hello all
I’m preparing a tutorial on remote sensing with GRASS (already have 7 videos - in portuguese - here: https://www.youtube.com/c/SPAMLabUSP)
What I’m planning now is to run i.landsat.toar and i.atcorr, and then compare the results with the surface reflectance products from Landsat collection 2.
I got it all running but the results are a bit different and it seems that the “range” and “rescale” options are the ones to tweak.
checking the metadata:
L2 before scale factor: {‘min’: ‘3783’, ‘max’: ‘65535’}
L2 after scale factor: {‘min’: ‘-0.0959675’, ‘max’: ‘1.6022125’}
L1 radiance at sensor: {‘min’: ‘-6.2’, ‘max’: ‘191.6’}
L1 reflectance dos1: {‘min’: ‘0’, ‘max’: ‘0.398754597845553’}
L1 reflectance 6S: {‘min’: ‘8.560894e-11’, ‘max’: ‘255’}
I can use the min/max from radiance-at-sensor as the “range” in i.atcorr, but what would be best for the “rescale” option? If I don’t set it, I end up with 0-255
values. How to get the floating-point result?
thank you for any input
Carlos
···
Prof. Carlos Henrique Grohmann
Institute of Energy and Environment - Univ. of São Paulo, Brazil
- Digital Terrain Analysis | GIS | Remote Sensing -
http://carlosgrohmann.com
http://orcid.org/0000-0001-5073-5572
Can’t stop the signal.
Hi Carlos,
Did you try with rescale=0,1? Or 0,10000 and then divide the result by 10000?
Vero
El mar, 31 ago 2021 a las 16:43, Carlos Henrique Grohmann de Carvalho (<carlos.grohmann@gmail.com>) escribió:
Hello all
I’m preparing a tutorial on remote sensing with GRASS (already have 7 videos - in portuguese - here: https://www.youtube.com/c/SPAMLabUSP)
What I’m planning now is to run i.landsat.toar and i.atcorr, and then compare the results with the surface reflectance products from Landsat collection 2.
I got it all running but the results are a bit different and it seems that the “range” and “rescale” options are the ones to tweak.
checking the metadata:
L2 before scale factor: {‘min’: ‘3783’, ‘max’: ‘65535’}
L2 after scale factor: {‘min’: ‘-0.0959675’, ‘max’: ‘1.6022125’}
L1 radiance at sensor: {‘min’: ‘-6.2’, ‘max’: ‘191.6’}
L1 reflectance dos1: {‘min’: ‘0’, ‘max’: ‘0.398754597845553’}
L1 reflectance 6S: {‘min’: ‘8.560894e-11’, ‘max’: ‘255’}
I can use the min/max from radiance-at-sensor as the “range” in i.atcorr, but what would be best for the “rescale” option? If I don’t set it, I end up with 0-255
values. How to get the floating-point result?
thank you for any input
Carlos
–
Prof. Carlos Henrique Grohmann
Institute of Energy and Environment - Univ. of São Paulo, Brazil
- Digital Terrain Analysis | GIS | Remote Sensing -
http://carlosgrohmann.com
http://orcid.org/0000-0001-5073-5572
Can’t stop the signal.
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