[GRASSLIST:1445] Re: gtopo30 California errors!

Markus Neteler neteler at geog.uni-hannover.de
Mon Feb 12 04:00:48 EST 2001

On Sun, Feb 11, 2001 at 05:05:21PM -0800, ECIS Mail wrote:
> All:
> 	I've consolidated many gtopo30 DEM files covering the North American
> Continent and have been doing a quality check on the info, mostly over
> California. I find California has a new geographic feature I was not aware
> of. It is a moat surrounding the foothills of the Central Valley ranging
> from a few meters to more than a hundred meters below sea-level. (Was this a
> big quality control hole in the otherwise excellent gtopo30 project, or did
> a hacker place modified DEM files in place of the originals.  DEM
> documentation indicates my lowest point in the combined dataset should be
> Death Valley, Ca. at -79 meters?).	Last I checked the peripheral canal is
> not yet built do to public opinion.
> 	I am curious as to whether anyone else has experienced and/or resolved this
> issue, and what steps were taken to make the corrections.  I need a solution
> soon as I think my small humble abode is going under in its current
> location, at least according to the gtopo30 DEM, and I'd like to bring it
> back up to the correct elevation. :-)
> 	If there are other errors around the N. American Continent in regards to
> the gtopo30 dataset please let me know. I am also looking for other
> potential 'free' DEM data sources with the same or better resolution as
> gtopo30.
> 	If you can help with either issue please drop a line to kcross at ecis.com.


you may check the GLOBE DEM 30 data, they could be of better quality:


 Markus Neteler

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