tomjnx wrote:
Urgh no, pseudoranges are the only thing the GPS measures (unless it has augmentation input, like barometric pressure, gyro, wheel revolution sensors), so it is used all the time. Pseudo because it’s not actually a range, but the signal propagation time for the satellites to the receiver converted to distance (with some errors, like ionospheric added)
Hmmm. Both the Oxford Aviation Academy ATPL manual and the PPL/IR PBN Manual state that the term “pseudorange” is used only when calculating the initial fix, as the receiver does not have the correct time at that point.
The Wikipedia article you linked to also says that the term pseudoranges is used “with unknown receiver clock offset”.
I spoke to the guy at Navtech (post #1) and they get true heading to 0.5 of a degree by comparing the carrier phase. It is not done by getting two GPS positions and working out the heading.
They get pitch, roll & yaw (heading) measurements in one go.
