Easy technique to measure the speed of your quadcopter, or any FPV or camera equipped RC vehicle. Since this was published I have learned that football goals are 360 feet from goal to goal so you will need to adjust your math accordingly. The concept is still the same though.
Here is a link to the speed calculator shown in the video:
Without grid lines on the field it is hard to tell exactly where the goalposts sit, but since they are at the back of the end zones make sure you account for it and use 120yds between posts at either end of the field!! You’re going faster than you calculate here!!!