Hi,

On the other forum, guys are always talking about how they 'dopplered' some video to verify speed. How's that done? Can someone do it with my F-15 vids? I'm curious about the speed, but don't have a radar....

You use software like Wave-o-scope to measure the doppler shift of the sound of the motor in a video or audio recording of the aircraft flying by. It works well with EDF, but not so well with recordings of turbine or IC aircraft.

There are also apps for iphone and android that will do it in real time. Again, good for EDF not so good for turbine or IC.<br type="_moz" />

Shaun here is a link to a guy that made one for android and Iphones. It says your speed after the pass and all you do is leave it in your pocket. But doubt it works for turbine..

http://www.rcgroups.com/forums/showt...hlight=android

It doesn't work worth a crap for turbines unfortunately

I've Just download this apps to my phone and testing its out on youtube RC pylon race. I'm getting some readings but not sure if its correct.

Even when doppler software is working correctly it has to be temperature adjusted and the readings are only as good as the recordings. The pilot must hold a constant throttle setting and fly reasonably close to the microphone (in any event the accuracy improves the closer to the microphone the pass is). Throttle changes will bugger the readings.

If you change the prop size on the same plane, will it affect the speed reading, Or is this reading base only when the hi frequency shifting to low?

Doppler shift only.

Got it

Thank you