[GRASS-user] i.atcorr: which is the meaning of range parameter?

[Veronica Andreo]

Hi all,

I'm using i.atcorr for atmospheric correction of Pleiades imagery. The data
comes as DN in 12 bits. Reading the manual of i.atcorr, I get that I must
provide radiance data. Hence I converted each band to radiance using gain
and bias from the metadata. Now, for the range parameter in i.atcorr, I
assume I must pass the min/max output of r.info for each band. There's no
extra info in the metadata about theoretical range for each band.

In the i.atcorr manual and in some older emails, I read for example, that
the range for Sentinel 2 is 1 to 10000. However here [1] it says:
"Per-pixel radiometric measurements are provided in Top Of Atmosphere (TOA)
reflectances along with the parameters to transform them into radiances".
AFAIU, 1,10000 is TOA range.

So, I'm a bit lost... What is really this range parameter representing?

Thanks much in advance

Vero

[1]
https://earth.esa.int/web/sentinel/user-guides/sentinel-2-msi/product-types/level-1c
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