For one,
it would be useful for my records (I keep application info on hand) to know the flight rpm of the engine.
Video and sound recordings, and the doppler measurements are an effective way to do that.
In the past, the vidoe analysis has been corrolated to GPS, radar, and air data information. The more data, the better
In most cases, a flight video and sound recordings have proven useful for gathering several data points.
If one becomes available..... it will be nice to take a look at.
Hopefully the thread here stays on track.
Bob