Reply to: Re: [Paparazzi-devel] distance measurement for landing. (Electro-Technik)

[Chris]

> "Even if local atmospheric pressure could be measured perfectly
> accurately, with no errors, would this be the best parameter to use to
> facilitate an automatic landing?"

From what  i have found out so far by reading and thinking all possible 
scenarios a barometer will not do the job.
What is needed is a definite, accurate and dependable method to measure 
the distance from the ground with an accuracy of at least 10cm and a 
latency of no more than 40ms.
Something like
1) someone sitting to the landing gear with a hand held
   laser distance meter :-)
2) A laser or optical  range meter but for all terrains.
3) A UWB range finder
4) A normal RF range finder
5) A powerful ultrasonic range finder.
6) A vision range finder either on the airplane or at the ground station.
6) a wire connected to a potentiometer which drags below the
   aircraft  (say 50 cm lower) :-)
Chris