Originally Posted by mm43
Following the Hyperveloce & Shadoko posts around the same time, I have come to the conclusion that the MH370 AES wasn't using the P Channel to determine and correct for the SAT / AES Doppler, but was using hardware/software operating to the principles described in the patent.
As hamster3null has pointed out, the requirement is that the AES assigned Tx frequency when corrected for the perceived Doppler shall be within 335Hz of the SAT assigned channel frequency when received at the SAT. So if the AES was using the P Channel method to create the correction, there would be close to zero BFO at the SAT, and obviously that was not the case. It would be safe to assume that the AES SDU software is using a fairly loose algorithm to correct for the SAT position and motion then compute the Doppler associated with its own (AES) position and motion. The AES Tx frequency arriving at the SAT is "offset", which seems to leave the satellite reporting the residual Doppler shift (BFO) to the GES.