I've looked over the calculations and I think they are making a very shaky assumption. The BFO-bias is calibrated why the plane is on the ground, and they assu

I've looked over the calculations and I think they are making a very shaky assumption. The BFO-bias is calibrated why the plane is on the ground, and they assume it is constant over time, temperature, air-pressure etc. This is probably not a valid assumption under any circumstances, given that there is no atomic frequency standard involved and probably not even an OCXO. Given that MH370's inmarsat-terminal was powered off for something like an hour during which environmentals may have been extreme and even outside specs, the assumption of a constant bias certainly have no legs to stand on in this particular case. If the terminal used something like a 1PPM milspec 100MHz TCXO, I would guess is that the BFO bias could be anywhere between 0 and 300Hz after the 18:25Z logon. I have not tried to replicate their trajectory estimation using this uncertainty, but by eye-balling it, it vastly increases the uncertainty of the resulting location. The validations they have done using other aircrafts involves BFO's running in nominal mode throughout, and therefore provides no information about how the BFO bias might change after power on/off or extreme environmentals.