R: [GRASS-windows] elevation data error?

[marco.pasetti at alice.it]

Hi Simon,
 
did you set the z-exag parameter?
Since lat/long data are in decimal degrees while elevation is in meters, you must set the correct value for the z-exag parameter.
The transformation from decimal degrees to meters is not univocal, because it depends on the geographic zone you're working on, but we can assume a generic (mean)transformation value and set the z-exag as follows:
 
in the z-exag field type 8.9606e-6 and then enter
 
I hope this helps,
 
Marco

________________________________

Da: grass-windows-bounces at lists.osgeo.org per conto di Simon Watkins
Inviato: lun 09/06/2008 10.27
A: grass-windows at lists.osgeo.org
Oggetto: [GRASS-windows] elevation data error?


Hi,

New to GRASS, and running native 6.3.0 on windows Vista.

I have downloaded some finished 3 arc sec SRTM data from the National Map Seamless Server in both GeoTIFF and ArcGRID format, however I am having troule in getting it to display as 3D.  I imported it via r.in.gdal and this seemed to work, however when I first load the layer it shows in the map display as a single colour block.  Clicking 'Map display fills window' seems to show the raster properly, however NVIZ still displays nothing.
Use of the profile tool gives the error 'elevation range for selected raster is zero', and the query tool outputs '(Lat)|(Long)| |211' for any cell.  The r.info <http://r.info/>  module shows a data type of FCELL and the correct map area and range of data.

Any pointers would be greatly appreciated,

Simon.

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