[GRASS-dev] Does SUN_ELEVATION in Landsat's MTL file mean zenith for i.topo.corr?

[Nikos Alexandris]

Sorry for cross-posting.

I would like a confirmation for the following, regarding i.topo.corr:

Is SUN_ELEVATION the requested zenith parameter (by i.topo.corr)?

So, given the entry "SUN_ELEVATION = 45.38304417" in the the metadata file 
"LT51840322011266MOR00_MTL.txt", then, the production of an illumination model 
requires "zenith=45.38304417".

Or is it "zenith = 90 - SUN_ELEVATION", thus it becomes
zenith = 90 - 45.38304417 = 44.616956

?

Thank you, Nikos