[GRASS-user] Project from UTM to State Plane & define region

Rich Shepard rshepard at appl-ecosys.com
Thu Sep 23 08:12:43 PDT 2021


Having created a new location using EPSG:2856 I tried to reproject a mapset
that defines the region I want to use for this project:
r.proj loc=<old_location_name> map=bathymetry in=local_depths

The result was not as I expected:
Found 3 possible transformations
************************
Operation 1:
Description: Inverse of SPCS83 Washington South zone (meters) + Inverse of
NAD83 to NAD83(HARN) (28) + UTM zone 10N

Area of use: United States (USA) - Oregon and Washington.

Accuracy within area of use: 0.05 m

PROJ string:
+proj=pipeline +step +inv +proj=lcc +lat_0=45.3333333333333 +lon_0=-120.5
+lat_1=47.3333333333333 +lat_2=45.8333333333333 +x_0=500000 +y_0=0
+ellps=GRS80 +step +inv +proj=hgridshift +grids=us_noaa_WO.tif +step
+proj=utm +zone=10 +ellps=GRS80
************************

This is the most appropriate as the other two are used in the whole world
and states other than Washington and Oregon.

But, I don't know how to use this information now that GRASS gave it to me.

The second problem is:
ERROR: Input raster map is outside current region

> g.region -p
projection: 99 (NAD83(HARN) / Washington South)
zone:       0
datum:      nad83harn
ellipsoid:  grs80
north:      1
south:      0
west:       0
east:       1
nsres:      1
ewres:      1
rows:       1
cols:       1
cells:      1

I need help to get out of the weeds in which I floundered. Apparently
creating the location with the EPSG code of 2856 was insufficient to define
all CRS parameters and the region.

TIA,

Rich




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