<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html style="direction: ltr;">
<head>
<meta content="text/html; charset=ISO-2022-JP"
http-equiv="Content-Type">
<title></title>
<style>body p { margin-bottom: 0cm; margin-top: 0pt; } </style>
</head>
<body style="direction: ltr;" bidimailui-charset-is-forced="true"
text="#000000" bgcolor="#ffffff">
On 01/01/2012 01:38 AM, <a class="moz-txt-link-abbreviated" href="mailto:SGW00412@nifty.com">SGW00412@nifty.com</a> wrote:
<blockquote cite="mid:Jxh_N9utk2G80Q2px_leJzvQ1@nifty.com"
type="cite">
<pre wrap="">Dear grass users;
I would like to create 500m dem from 90m dem (SRTM).
So, I am going to write a script as follows...is it right ?
</pre>
</blockquote>
<br>
Here's how I would do:<br>
1- Import the srtm, set resolution and region to this new raster:<br>
g.region -p rast=<srtm_raster><br>
<br>
2- Get the current region extents:<br>
v.in.region out=srtm_region<br>
THis creates a vector rectangle of the current region<br>
<br>
3- Now switch to the UTM location, and project the original vector
region to UTM...<br>
v.proj in=srtm_region loc=<wgs84_location>
map=<wgs84_mapset> out=srtm_region<br>
...and reset the current region to that new vector...<br>
g.region -p vect=srtm_region<br>
...but also reset the resolution to 500 m...<br>
g.region -p res=500<br>
<br>
4- Now you can run r.proj to reproject the original srtm to your UTM
region, and it will do the interpolation for you. The following
quote is from the r.proj man page:<br>
"Note that, following normal GRASS conventions, the coverage and
resolution of the resulting grid is set by the current region
settings, which may be adjusted using g.region."<br>
...so...<br>
r.proj in=<srtm_raster> loc=<wgs84_location>
map=<wgs84_mapset> out=srtm_raster_utm method=bilinear<br>
(You can choose which interpolation method to use, See the man page)<br>
<br>
That should do it.<br>
--<br>
Micha<br>
<br>
<br>
<blockquote cite="mid:Jxh_N9utk2G80Q2px_leJzvQ1@nifty.com"
type="cite">
<pre wrap="">(1)import with 'r.in.srtm' command.
(2)set resolution with 'g.region' command.
SRTM is 90m resolution...
(3)exchagen a projection from latlon_wgs84 to utm_xx with 'r.proj' command.
( because initial projection of SRTM data is latlon_wgs84...)
(4)change resolution with 'g.region' res=500 (meter).
(5)create a point vector with 'r.to.v'(col=value) command.
I feel whether the target value is acquired by only change of resolution (90m->
500m).
May I use 'r.surf.rst' ?
Best,
Yasuo shimada: Japan weather associaton.
_______________________________________________
grass-user mailing list
<a class="moz-txt-link-abbreviated" href="mailto:grass-user@lists.osgeo.org">grass-user@lists.osgeo.org</a>
<a class="moz-txt-link-freetext" href="http://lists.osgeo.org/mailman/listinfo/grass-user">http://lists.osgeo.org/mailman/listinfo/grass-user</a>
This mail was received via Mail-SeCure System.
</pre>
</blockquote>
<p><br>
</p>
</body>
</html>