Hi Bulent,
See some answers below.
Michael
____________________
C. Michael Barton
Director, Center for Social Dynamics & Complexity
Professor of Anthropology, School of Human Evolution & Social Change
Arizona State University
voice: 480-965-6262 (SHESC), 480-727-9746 (CSDC)
fax: 480-965-7671 (SHESC), 480-727-0709 (CSDC)
www: http://www.public.asu.edu/~cmbarton, http://csdc.asu.edu
On Jul 28, 2010, at 2:04 AM, <grass-user-request@lists.osgeo.org> wrote:
Date: Wed, 28 Jul 2010 12:04:06 +0300
From: Bulent Arikan <bulent.arikan@gmail.com>
Subject: [GRASS-user] patching
To: grass-user@lists.osgeo.org
Message-ID:
<AANLkTikYu76GGJ_nR2j=L8DUmPAdMJAP011kz98fYOSP@mail.gmail.com>
Content-Type: text/plain; charset="iso-8859-1"Dear List,
I have several ASTER GDEM (originally Latlong) images that I want to
reinterpolate from 30 to 10 m res. I also need to patch these images. I am
not sure whether:- I should patch them in Latlong using r.series, reproject into UTM and
interpolate them using r.resamp.rst or
If you patch, use r.patch, not r.series.
- reproject images individually into UTM, interpolate individually using
r.resamp.rst and then patch them using r.series.
IMHO, your first option will be the most accurate. However, the reprojection and resampling will take a long time because you will have a very big map to work with.
Also, read the manual for r.resamp.rst carefully. IIRC, there are a couple tricks you need to remember about how to set the region resolution prior to running r.resamp.rst.
As an alternative, you can create a point file using r.to.vect, so that you get a point for the center of each original raster cell. Then you can set the region to 10m and use v.surf.rst or v.surf.bspline to interpolate a new map.
So far, I tried the second option. After cubic reprojection and
interpolation to 10m the tiles have little borders of NULL areas when I
display them together. They don't go away when patched.
This is because you tried to patch after reprojection.
I will appreciate any advice
Thanks.
--
B?LENT ARIKAN, PhD
School of Human Evolution and Social Change
Arizona State University
Tempe - AZ
85287-2402