[GRASS-user] r.proj issue [RESOLVED]

Rich Shepard rshepard at appl-ecosys.com
Mon Sep 16 07:21:09 PDT 2019


On Sun, 15 Sep 2019, Markus Metz wrote:

> You should now use
> r.proj loc=Oregon map=topography in=n45w121
> and not r.unpack, that is a completely different workflow that has nothing
> to do with reprojection.

Markus M,

I've tried two approaches to getting the 10m DEM (upper, left corner at 46N,
123W) into the project location: directly reprojecting from the import
location (in lon-lat decimal degrees), and unpacking from the r.packed map
in the statewide location (which successfully was projected from the import
location).

The locations are apparently not the problem; the statewide and project
locations are the same. I changed the project region to the state boundary
(the same region as the statewide location) and this makes no difference.

Both approaches fail; the resulting map has only 500 columns while the
source map has 11k+ columns.

Stepping back from this problem I recognized that the furthest western
longitude for the DEM immediately south of this problem one is too far to
the east at 121W. So, I can't use the 10m DEMs for lack of coverage.

I'm going back to the LiDAR data (which covers the entire north coast) and
can always resample to 5m or 10m if 1m is too fine for analyzing sediment
transport dynamics and fish populations in the entire river network.

I apppreciate your comments as well as those by Helmut and Markus N.

Best regards,

Rich


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