[GRASS-user] shaded relief of srtm tiles

[thorsten]

Thanks a lot!!
now i got it.
and Merry Xmas!

Maciej Sieczka wrote:

>thorsten wrote:
>  
>
>>thank you Hamish,
>>
>>patching works fine  ( http://www.flickr.com/photos/h2guide/329431459 ),
>>but i try to create a shaded relief of a hughe area,
>>so i will have to process it tile by tile.
>>
>>what i am actually doing is:
>>
>>r.in.srtm input=N42W005 output=tile  #r.in.srtm input=N42W004 output=tile
>>g.region rast=tile
>>r.colors map=tile rules=srtm
>>r.shaded.relief map=tile shadedmap=relief altitude=44 azimuth=270
>>units=meters
>>r.his h_map=tile i_map=relief r_map=final.red g_map=final.green
>>b_map=final.blue
>>r.composite red=final.red green=final.green blue=final.blue levels=32
>>output=final;
>>
>>"final" is the shaded and colored relief.
>>
>>what do you mean by "absolute" color table?
>>i am  using the  predefined color table "srtm"
>>    
>>
>
>That's OK. The problem is that r.shaded.relief script internally uses
>"r.colors "$ELEVSHADE" color=grey" internally. Since the "grey"
>colortable is defined as follows:
>
>$ cat /usr/local/grass-6.3.cvs/etc/colors/grey
>0% black
>100% white
>
>the colortable depends on min/max value in the input raster.
>
>A workaround: you can check the max and min height in *all* your
>rasters, choose the maximal max an minimal min out of them, and modify
>the r.shaded.relief script to assign your absolute-grey colortable instead.
>
>Maciek
>
>  
>