Hey,
I've "cropped" six maps with six different masks [see: masks.gif].
As r.mapcalc is so powerful, I guess there is a way to merge the cropped maps together?!
I would be thankful for suggestions.
Cheers
Axel
(attachments)
Axel, if you have six maps that are already cropped (not just displayed that way with d.rast and a mask), then you can r.patch them together. If you were just showing a display, then with a mask in place, do
r.mapcalc newrast=oldrast
to create a new raster using the mask.
Hope this helps,
Ian
On Aug 4, 2005, at 6:14 AM, Axel Orth wrote:
Hey,
I've "cropped" six maps with six different masks [see: masks.gif].
As r.mapcalc is so powerful, I guess there is a way to merge the cropped maps together?!I would be thankful for suggestions.
Cheers
Axel<masks.gif>
HI.
I have downloaded an SRTM DEM (3 arc sec) for parts of Patagonia.
I need to validate the DEM against my own set of topographic data. I would like to get pointers to documents describing validation methods. Anyone in this list who can provide leads and hints to access available documentation?
Thanks
Armando Scalise
Armando:
I think the easiest way to do it is to take the DEM value and your
own measurements and do a regression between the two. If there's a tight
fit (low R2) then you can use the slope and offset to correct one set of
data to "fit" another.
--jb
--
Jonathan A. Greenberg, PhD
NRC Research Associate
NASA Ames Research Center
MS 242-4
Moffett Field, CA 94035-1000
Office: 650-604-5896
Cell: 415-794-5043
AIM: jgrn307
MSN: jgrn307@hotmail.com
-----Original Message-----
From: owner-GRASSLIST@baylor.edu [mailto:owner-GRASSLIST@baylor.edu] On
Behalf Of Armando Scalise
Sent: Thursday, August 04, 2005 3:02 PM
To: GRASS international
Subject: [GRASSLIST:7792] SRTM DEM data validation (Not a GRASS specific
thread)
HI.
I have downloaded an SRTM DEM (3 arc sec) for parts of Patagonia.
I need to validate the DEM against my own set of topographic data. I
would like to get pointers to documents describing validation methods.
Anyone in this list who can provide leads and hints to access available
documentation?
Thanks
Armando Scalise