Thanks for looking. Just musing over an idea this afternoon: if I had a radio controlled plane, I could obviously calculate its airspeed based on pings and the known speed of sound if it was traveling on a straight path away or towards me.
Now lets say I need to get it's ground speed if it was traveling a line perpendicular to my viewpoint. Here, measuring scheduled pings won't reveal the correct speed because if the plane was flying in a perfect circle with me at the circle's center the speed would appear to be zero since the distance or ping response has no deviation.
Ok, so what about doppler shift? I think some of my brain came out of my ear when trying to picture how that would work in a perfect circle with me at it's center, so let's keep it simple and visualize the straight path that is perpendicular to where my view point (flying left to right or right to left in my viewable area).
Assuming I had a radio control that could receive some sort of pings from the RC aircraft, could I use Doppler Shift to calculate the aircraft's airspeed?
What type of sensor could interpret the relative "bunching" of sound waves that we know as Doppler Shift? (Yes, obviously I want to know the ground speed of my RC airplane. I know this is possible with GPS, but I am a software engineer so naturally I make things more complicated than they need be!)
**Disclaimer: I am not a physicist, I am a software engineer. Apologies in advance if I have asked a dumb question that made Newton (or Doppler in this case) spin in his grave!