[Proj] Understanding 2D Helmert
andre+joost at nurfuerspam.de
Fri Oct 26 08:43:03 EST 2018
since PROJ 5.2 now has made its way into the OSGEO4W binaries, I try to
understand the new features.
I started up with the 2D helmert transformation with this command line:
echo 1000 0 | proj +proj=helmert +convention=coordinate_frame +x=0 +y=0
This should rotate a point with X=1000 Y=0 meters by theta=-5 around the
But the result of "17.45 0" does not really make sense to me.
X=2000 results to a new X=34.91.
Can anybody shed a light on this?
More information about the Proj