[GRASS-dev] i.atcorr produces 'nan' values for certain RapidEye bands

Markus Neteler neteler at osgeo.org
Wed May 10 09:31:26 PDT 2017

On Mon, Mar 6, 2017 at 10:57 AM, Florian Detsch
<florian.detsch at staff.uni-marburg.de> wrote:
> Dear all,
> I am experiencing rather strange behavior when using RapidEye
> top-of-atmosphere (TOA) reflectances as input for i.atcorr. Here, some
> band-specific output solely contains nan values, whereas other
> atmospherically corrected layers look just fine.
> For replication purposes, sample RapidEye Ortho Level 3A data. which is
> provided by third parties, is publicly available from GitHub
> (https://github.com/italocegatta/rapidr/tree/master/inst/extdata). At-sensor
> radiances, which show the same strange behavior as TOA reflectances, can
> easily be calculated therefrom through multiplying the digital numbers of
> all five bands by 0.01. The SRTM digital elevation model (DEM) and
> band-specific parameter files, that serve as additional input parameters for
> i.atcorr, are available from Dropbox
> (https://www.dropbox.com/sh/3j1nvveblrrp0z1/AABo5SPww63uX80hacpK4A59a?dl=0).
> Aerosol optical depth and mean elevation specified in the parameter files
> have been taken from MODIS (MOD/MYD08_D3, V006) and SRTM, respectively. The
> remaining parameters are either taken from the accompanying metadata file or
> inherit standard values as specified in the GRASS 7.2 i.atcorr manual
> (https://grass.osgeo.org/grass72/manuals/i.atcorr.html).
> Now, when I run i.atcorr in GRASS 7.2 (Ubuntu 16.04.2 LTS, 64-bit or Windows
> 10, 64-bit - I have tested both) using the above parameter file, the
> atmospherically corrected image for band 1 looks as expected.

Did you ever use "trunk", i.e the development version? I updated the
i.atcorr filter functions updated for Rapideye on Dec 14, 2016.

(this I backported for the future GRASS GIS 7.2.2 three days ago).

Please let us know if the version in trunk (or the weekly 7.2
snapshot) works ok for RapidEye. Unfortunately I have no time in this
period to test with the aforementioned sample data myself.


Markus Neteler, PhD
http://www.mundialis.de - free data with free software

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