Find Your Lost Quadcopter Using LaForge / True-D / RealACC / Etc...

Thanks to Jacob Orchard, Bob Ulrich, and the other folks at Microsoft Channel 9 Drones Garage for inviting me to Redmond to fly with them and shoot some videos. If you want to see the episode of Drones Garage that I was on, it's here:
If you lose your quadcopter in the grass, the best way to find it is with a beeper. But what you haven't installed a beeper, or if you're too far away to hear the beeper? Your Fatshark Diversity Module can help you find the copter.
RF direction finding means using a directional antenna and a signal strength meter to home in on the location of a transmitting device. As long as the copter is still powered up and the vTX is transmitting, you can find it using your FatShark goggles!
I am using LaForge in this example, but this exact same trick works just as well with any module that has an RSSI display, such as Furious FPV True-D, RealACC, and so forth.