rotateGCP
The horizontal seismograms are rotated to the great circle path. The channel codes are changed to end in R for radial or T for transverse, so BHN and BHE would become BHR and BHT. The actual channel information is not changed, so if you need the Channel object associated with these transformed seismograms, you should use the ChannelGroup.getChannel(ChannelId) method as it will detect the R and T ending and give the appropriate transformed Channel.
Example
<rotateGCP/>
Places this can be found
In waveformVectorProcess there is a choice between all of the following