Originally Posted by
Goldenrivett
GPS will give you accurate track and ground speed.
The calculated wind is solved using track & ground speed, heading and TAS. TAS is calculated using IAS and air density. (If IAS is rubbish, then TAS is rubbish).
Therefore TAS-> IAS calculation will be rubbish.
I don't understand what point you are trying to make.
TAS is calculated using IAS and air density
Correct.
And the corollary is that if the requirement (as in this case) is the opposite way round, i.e. to calculate IAS from TAS, you get TAS from the laser sensor (which is what this thread is about) and air density from altitude (either baro- or GPS-derived).
What's your problem with that?