[GRASS-user] <sigh>Not this pest again!

[Hamish]

Richard Chirgwin wrote:
> ... Having given up on the Australian Communications & Media Authority
> DEM because it won't import into Grass-GIS (there seems to be some
> fiddling to keep the DEM hidden behind a silly Windows app),

with the exact file size, expected rows & columns, and possibly byte info
and geographic extent known about it we still might be able to give some
guesses about how to get around that. Or is it known for sure that they've
taken steps to encrypt it?


> I'm turning to other DEMs.
> 
> The NASA SRTM seems as if it would suit my purposes, except that using
> r.in.srtm I get a lovely image with no elevation data. So r.what comes
> up with latitude, longitude, and null, eg:
> 150 | -34 | | *

It probably worked, you just need to run g.region.

I just tried:
wget ftp://e0srp01u.ecs.nasa.gov/srtm/version2/SRTM3/Australia/S34E150.hgt.zip

r.in.srtm in=S34E150
r.info -r S34E150
min=-32
max=1360

g.region rast=S34E150
r.univar S34E150
..
..
..
d.mon x0
d.rast S34E150

r.fillnulls in=S34E150 out=S34E150.filled


and it all seemed to work ok.


Another way is get the data from Geoscience Australia's WMS server,

g.region n= s= w= e= res=...
r.in.wms -l -g mapserv="http://www.ga.gov.au/wms/getmap?dataset=national&"

I imagine GA are much more GIS friendly than the media censors.

If you still have trouble with obtaining datasets, you might ask for help
on the OSGeo Aust-NZ mailing list.


> QGIS imports and displays the HGT file okay, but misinterprets the
> elevation data as band data (so for Katoomba, 1000m above
> sea level, QGIS says the band is 1004).

no idea.

> There aren't that many options in r.in.srtm, so I don't think I could
> have gotten any of them wrong...

probably it worked ok you just have to adjust the zoom with g.region.


Hamish