In theory it is fairly simple, you simply go to a number of locations (greater than 3) and record signal strength. That lets you tell if the sender is farther a

In theory it is fairly simple, you simply go to a number of locations (greater than 3) and record signal strength. That lets you tell if the sender is farther away or closer. You can run the numbers yourself or alternatively throw it at a computer to figure out where some transmitter has to be to produce those transmit powers. Alternatively, you take your receiver and record signal strength, then you walk and see if it's stronger. You then just walk in the direction the signal becomes stronger in.