Microphone-based air speed measurement

[ian329]

Hi Guys,
As per title. I want to use a microphone to measure air speed on a UAV. I envisage two methods of achieving this...

1. amplifying, filtering & then integrating the output from a microphone to produce a voltage level, convert the voltage to a digital signal and calibrate to produce a final value. (the reason I say filter is that I may need to remove the aircraft motor noise)

2. amplifying and then rectifying the output from a microphone, convert to digital and use a counter to produce the value.

In both cases the amplifier may not be necessary, but i'm not too sure. I assume I will need to mount the mic in a tube of some sort to channel air to it, perhaps also introducing a disruption to make more noise!

Does anyone have any tips on how I can achieve this or if i'm on the right track? Any help appreciated!
Cheers
Ian

[sjb]

For a capacitative microphone, can you point it forwards so the air presure squashes the diaphragm, then measure the capacitance?

At high speeds, air pressure would be higher, the microphone plates nearer, and capacitance higher.