At 21:13 4/05/99 -0400, you wrote: >how about measuring different > >glue 2 thermistors to 2 resistors >put the two resistors in series on a constant current source (constant >output heater) >put the one pair in the airflow >the other pair inside the plane > >measure resistance of both thermistors >the heatloss from airspeed should be a good indication of airspeed >(needs small mass so reaction speed is sufficient) >use the pair inside the plane to compensate for air temperature >use a 2 dimensional lookup table for windspeed > >Peter Do you think that it will work well at temperatures around -45C? :-) I guess that an altimeter would also be required, or another set of thermistors outside to measure air temp. Perhaps we should look into rocket control, as there are some methods of placing holes in the body, and measuring and calculating the disturbance to airflow-> speed and direction etc. Dunno much about it but. I guess that it would take more than a PIC to do the complex calculations. Dennis