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

Markus Neteler neteler at osgeo.org
Mon Jan 15 23:32:56 PST 2018

On Fri, Jan 12, 2018 at 10:42 AM, Markus Metz
<markus.metz.giswork at gmail.com> wrote:
> On Fri, Jan 12, 2018 at 8:58 AM, Markus Neteler <neteler at osgeo.org> wrote:
> The spectral filter functions for RapidEye in i.atcorr are strange. E.g.
> band 2 (green) is supposed to cover the range 520 - 590 nm, but in iwave.cpp
> this band covers the range 424 - 876 nm. Further on, the file rapideye.csv
> and the values in IWave::rapideye() do not match, a lot of 0.001 values have
> been inserted where there should be zero. In rapideye.csv, there are gaps in
> filter functions, e.g. for green from 598 to 763 nm, then again from 773 to
> 876 nm. In the range 424 - 508 nm, there are also a few small blocks with
> values > 0 separated by large blocks of missing values.

This is the source which was used:

Maybe something went wrong?


> In short, there are too many too small values in the rapideye filter
> functions, causing numerical instability. This could be fixed upon
> initialization.
> Markus M

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