[GRASS-user] calculating slope in SRTM data from http://srtm.csi.cgiar.org/

GRASS GRASS user
1

Hi,

I'm using processed SRTM data from http://srtm.csi.cgiar.org/ the
current release is Version 3, which was a great improvement from V1
and 2 especially with 1/2 pixel shift, coastline boundary clipping and
filled holes.

I would like to ask others on using this dataset in calculating slope.
I now have a working GRASS database with SRTM imported (as integer).
In running r.slope.aspect, do I need to do further pre-processing of
the SRTM DEM? The 90m pixel size is OK for the purpose of the
research.

cheers,
maning

--
|---------|----------------------------------------------------------|
| __.-._ |"Ohhh. Great warrior. Wars not make one great." -Yoda |
| '-._"7' |"Freedom is still the most radical idea of all" -N.Branden|
| /'.-c |Linux registered user #402901, http://counter.li.org/ |
| | /T |http://esambale.wikispaces.com|
| _)_/LI
|---------|----------------------------------------------------------|

2

Hi Maning,

now have a working GRASS database with SRTM imported (as integer).

did you use r.in.gdal, right?

In running r.slope.aspect, do I need to do further pre-processing of
the SRTM DEM?

no, you don’t.

Marco

Da: grass-user-bounces@lists.osgeo.org per conto di maning sambale
Inviato: ven 09/05/2008 10.24
A: grass-user
Oggetto: [GRASS-user] calculating slope in SRTM data fromhttp://srtm.csi.cgiar.org/

Hi,

I’m using processed SRTM data from http://srtm.csi.cgiar.org/ the
current release is Version 3, which was a great improvement from V1
and 2 especially with 1/2 pixel shift, coastline boundary clipping and
filled holes.

I would like to ask others on using this dataset in calculating slope.
I now have a working GRASS database with SRTM imported (as integer).
In running r.slope.aspect, do I need to do further pre-processing of
the SRTM DEM? The 90m pixel size is OK for the purpose of the
research.

cheers,
maning

–
|---------|----------------------------------------------------------|
| _.-. |“Ohhh. Great warrior. Wars not make one great.” -Yoda |
| ‘-._"7’ |“Freedom is still the most radical idea of all” -N.Branden|
| /'.-c |Linux registered user #402901, http://counter.li.org/ |
| | /T |http://esambale.wikispaces.com|
| )/LI
|---------|----------------------------------------------------------|

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3

Marco,

now have a working GRASS database with SRTM imported (as integer).

did you use r.in.gdal, right?

Yes

In running r.slope.aspect, do I need to do further pre-processing of

the SRTM DEM?

no, you don't.

Alright, thanks!

cheers,

maning

--
|---------|----------------------------------------------------------|
| __.-._ |"Ohhh. Great warrior. Wars not make one great." -Yoda |
| '-._"7' |"Freedom is still the most radical idea of all" -N.Branden|
| /'.-c |Linux registered user #402901, http://counter.li.org/ |
| | /T |http://esambale.wikispaces.com|
| _)_/LI
|---------|----------------------------------------------------------|

4

On Fri, 2008-05-09 at 11:37 +0200, marco.pasetti@alice.it wrote:

Hi Maning,

> now have a working GRASS database with SRTM imported (as integer).

did you use r.in.gdal, right?

>In running r.slope.aspect, do I need to do further pre-processing of
the SRTM DEM?

no, you don't.

Marco

I also use this product. I didn't do anything but importing. Only, when
interpolating the DEM at a different resolution I follow someone's
advice and use bilinear interpolation.

Greets,

Nikos