i.atcorr [GRASS] - has anyone used it and actually had success?

Question

I am trying to apply i.atcorr to a landsat mosaic with GRASS. These are my 6S parameters:

18
01 31 22.10 178.940 -17.263
1
1
0
0.115
-0.270
-1000
 116

Everytime I run it, it returns me a raster with only one value. I've changed the values, I've tried with dummy data, I've read the documentation several times. I have read literally all the questions here in stack gis about the use of i.atcorr with GRASS, and in their mailing list as well. There seems to be a lot of people that has the same output, this sort of blank raster, but there is not a clear solution to this.

Has anybody applied this algorithm successfully to Landsat 8 and, if so, any idea on I am possibility doing wrong?

**Edit: GRASS GIS 7.4.4. on Windows 10.

Answer 1

I tried to duplicate your process (GRASS 7.4.3 on Debian) and it seems to work as expected. Here are the commands I used after downloading and unzipping the tile you used:

# Import the bands to GRASS
for t in 1 2 3 4 5 6 7 8 9 10 11; do r.in.gdal input=LC08_L1TP_074072_20140131_20170426_01_T1_B${t}.TIF output=lc8_b${t} --o; done 

# TOA reflectance
i.landsat.toar -r input=lc8_b output=lc8_toar metfile=LC08_L1TP_074072_20140131_20170426_01_T1_MTL.txt sensor=oli8 --o

# Three different 6s_params files with different last line 
# 116,117,118 for blue, green, red bands
# Atmospheric correction
for b in 2 3 4; do i.atcorr input=lc8_toar${b} out=lc8_atcorr${b} param=6s_params${b}.txt --o; done

The results (below) are composite of bands 4,3,2 (RGB). It doesn't look so impressive, maybe the correction parameters need to be tweaked. But it's definitely working. Note the -r flag to i.landsat.toar