[GRASSLIST:2799] Re: image correction tools

[Markus Neteler]

On Mon, Mar 01, 2004 at 11:49:12AM +0100, werchowyna at pf.pl wrote:
> hello Everyone!
> 
> this my first post to GRASSLIST
> 
> since it's not strictly GRASSy you may answer directly to me
> werchowyna at pf.pl
> 
> I'm looking for a Grass module/standalone software (both Linux and Windos)
> for radiometric (solar, atmospheric, topographic) correction of aerial and
> satellite images  of subalpine and alpine areas
> 
> open source/freeware/cheap preferably
> 
> can someone help?
> any ideas where to ask?

There is an implementation of "6S" in GRASS:
http://grass.itc.it/grass_addons.html
 -> i.atcorr: 6S atmospheric correction program (Christo Zietsman, South Africa)

Concerning terrain correction we are suggesting a simple method
with r.mapcalc etc in our book (http://mpa.itc.it/grassbook/).
Basically it is using the terrain geometry (slope, aspect), sun position
and the calculation of a normalized map. The upcoming second edition of
the book will describe a slightly improved method. It's not very
difficult.
An older version is here (my MSc thesis, 1999):
http://www.geog.uni-hannover.de/users/neteler/itc_irst/atmos_sma/9_atmos.html
(click onto the right buttons to proceed).

You should be sure to have an elevation model with a resolution
which corresponds to the resolution of the aerial or satellite image.

Best regards

 Markus

-- 
Markus Neteler     <neteler itc it>       http://mpa.itc.it
ITC-irst -  Centro per la Ricerca Scientifica e Tecnologica
MPBA - Predictive Models for Biol. & Environ. Data Analysis
Via Sommarive, 18        -       38050 Povo (Trento), Italy