ORIGINAL: Barry_DVRC
But how do I tell engine RPM? Can it actually be done with this program?
Here are the Doppler equations.
To get the RPM in the air, we have
f = 2 / (1 / Fgoing + 1 / Fcoming)
and
RPM = f * 60
To get Fgoing left click on one of the lines on top and then right click the line 5 lines over also at the top. Get the difference in frequency shown at the bottom and divide by five. Do the same thing at the bottom (same lines used for top measurement) to get Fcoming. you could use just one line apart but 5 when divided by 5 is more accurate.
There was some discussion in this thread about it.
http://www.rcuniverse.com/forum/m_70..._1/key_/tm.htm