from 47 CFR 87.145
(d) Aircraft earth stations must correct their transmit frequencies for Doppler effect relative to the satellite. The transmitted signal may not deviate more than 335 Hz from the desired transmit frequency. (This is a root sum square error which assumes zero error for the received ground earth station signal and includes the AES transmit/receive frequency reference error and the AES automatic frequency control residual errors.) The applicant must attest that the equipment provides adequate Doppler effect compensation and where applicable, that measurements have been made that demonstrate compliance. Submission of data demonstrating compliance is not required unless requested by the Commission.
It seems this requirement was not fulfilled by the airplane's equipment. Tests with other MAS 777 airplanes during the first two werks seem to have shown evidence that all those airplanes had the same behaviour.
My assumption is that a satellite is just a very wideband transponder and plays no active role in analysing. I am surprised that raw data are recorded in the ground station that allow a retrospective doppler analysis to this degree. I would have expected that only data packets would be stored, albeit with a timestamp, channel information, maybe beam antenna employed. But retrieving such small amounts of frequency deviation as 100 Hz from 1600 MHz requires raw data be stored.
Assuming the Doppler effect can be modified by a person on board is pure bs, though.
Last edited by threemiles; 30th Mar 2014 at 05:18.