Paul:

After reading some of your emails concerning home-brewed
engine management systems, I started thinking that it
might be fun to create an entire glass panel for an aircraft.



Since I am always "reinventing the wheel", I began
wondering if acoustical  airspeed instruments are ever
used on aircraft. Two transducers oriented longitudinally
in the air stream should be able to use the Doppler Effect to
easily calculate airspeed. Heterodyne the upstream signal
against the downstream signal. Airspeed should be a
multiple of the beat-frequency.

Robin

Why when a pressure sensor is $10? :)

Paul Lamar



A dopler sensor would be able to measure other things
as well such as the RW direction which would indicate
angle of attack, yaw and slip angles. It could do so
with a very low cost sensor. Of course it would also
require a means to melt ice. Sensors like this are
used on boats (See attached link)

http://www.maretron.com/products/wso100.php

Windy Farnsworth
Engineer