hello Everyone!
this my first post to GRASSLIST
since it's not strictly GRASSy you may answer directly to me
werchowyna@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?
cheers
Maciek Sieczka
On Mon, Mar 01, 2004 at 11:49:12AM +0100, werchowyna@pf.pl wrote:
hello Everyone!
this my first post to GRASSLIST
since it's not strictly GRASSy you may answer directly to me
werchowyna@pf.plI'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 areasopen 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
thank you for your help Markus
one thing more: how do I correct the effect of uneven lighting conditions in
aerial photos?
(some areas are brighter like if there was a spot-light or a flash cast on
it and some are unnaturaly dark)
Regards
Maciek
----- Original Message -----
From: "Markus Neteler" <neteler@itc.it>
To: <GRASSLIST@baylor.edu>
Sent: Tuesday, March 02, 2004 10:17 AM
Subject: [GRASSLIST:2799] Re: image correction tools
On Mon, Mar 01, 2004 at 11:49:12AM +0100, werchowyna@pf.pl wrote:
> hello Everyone!
>
> this my first post to GRASSLIST
>
> since it's not strictly GRASSy you may answer directly to me
> werchowyna@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.htm
l
(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
On Tue, Mar 02, 2004 at 04:24:15PM +0100, werchowyna@pf.pl wrote:
thank you for your help Markus
one thing more: how do I correct the effect of uneven lighting conditions in
aerial photos?
(some areas are brighter like if there was a spot-light or a flash cast on
it and some are unnaturaly dark)
That should be minimized by the (below) suggested terrain correction
which calculates the illumination based on the DEM and then normalizes
the brightness differences to make the photos appear as it were in
flat terrain.
Markus
Regards
Maciek----- Original Message -----
From: "Markus Neteler" <neteler@itc.it>
To: <GRASSLIST@baylor.edu>
Sent: Tuesday, March 02, 2004 10:17 AM
Subject: [GRASSLIST:2799] Re: image correction tools> On Mon, Mar 01, 2004 at 11:49:12AM +0100, werchowyna@pf.pl wrote:
> > hello Everyone!
> >
> > this my first post to GRASSLIST
> >
> > since it's not strictly GRASSy you may answer directly to me
> > werchowyna@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.htm
l
> (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
has anyone delt with aerial photo radiometrical correction in regard of the
vignetting effect?
it's an effect of unequal light distribution in the the wide angle lens
as an effect the center of the photo is brighter and corners/borders are
darker - the
further from the center the darker
my photos cover mountainous area
btw: thanks Markus for your remarks on topographic and atmospheric
correction
Maciek Sieczka