problem with horizontal components for stations exactly at the poles

[martinvandriel]

Obviously, coordinate transforms are not well defined for stations exactly at the north or south pole when using NEZ componenents. But: E and N should then at least just be some kind of rotated version of R and T, but they are not. Amplitudes are an order of magnitude to small then, while waveforms are ok. This is both the case in comparison to stations close to the pole for sources at arbitrary places as well as compared to the new rdbm mode.

I used receivers.dat in these tests.

I would guess this is somewhere in the coordinate transforms in postprocessing.F90