[Qgis-user] ITRF00

[Even Rouault]

On vendredi 13 décembre 2019 13:01:36 CET malcolm wrote:
> The proj definition below is what I am using to convert data using PostGIS
> from NAD83 to WGS84 in a separate application. This creates data that
> matches what is transformed from ArcMap using the ITRF00 transformation
> (which is default in the latest version). The NAD83 datum in PostGIS is
> simply towgs84=0,0,0,0,0,0,0. I am using the 3735 projection for NAD83
> (Ohio SP South).
> 
> +proj=lcc +lat_1=40.03333333333333 +lat_2=38.73333333333333 +lat_0=38
> +lon_0=-82.5 +x_0=600000 +y_0=0 +ellps=GRS80
> +towgs84=-0.9956,1.9013,0.5215,0.025915,0.009246,0.011599,-0.00062
> +units=us-ft +no_defs
> 

(adding back the list)

OK, so from the above parameters and digging into the EPSG database, it seems 
to be the NAD83(CORS96) to ITRF2000 transformation, with the omission of the 
time dependant terms:

$ projinfo -s "NAD83(CORS96)" -t ITRF2000 --spatial-test intersects -o PROJ
Candidate operations found: 2
-------------------------------------
Operation n°1:

unknown id, Conversion from NAD83(CORS96) (geog2D) to NAD83(CORS96) 
(geocentric) + Inverse of ITRF2000 to NAD83(CORS96) (1) + Conversion from 
ITRF2000 (geocentric) to ITRF2000 (geog2D), 0 m, USA - CONUS and Alaska; PRVI

PROJ string:
+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert 
+xy_in=deg +xy_out=rad +step +proj=cart +ellps=GRS80 +step +inv +proj=helmert 
+x=0.9956 +y=-1.9013 +z=-0.5215 +rx=0.025915 +ry=0.009426 +rz=0.011599 
+s=0.00062 +dx=0.0007 +dy=-0.0007 +dz=0.0005 +drx=6.7e-05 +dry=-0.000757 
+drz=-5.1e-05 +ds=-0.00018 +t_epoch=1997 +convention=coordinate_frame +step 
+inv +proj=cart +ellps=GRS80 +step +proj=unitconvert +xy_in=rad +xy_out=deg 
+step +proj=axisswap +order=2,1


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