Hi, I'm looking for a way to detect the location (in 3D) of an object with reference to another object. I'm looking for a solution that will be very cheap with reference to the receiver. The transmitter may be expensive, but the receiver must be cheap because I will need to have many (hundreds) of receivers and one main transmitter... Also this must be utilized over long distances. Can anyone help me out on a good medium? I can use 3 different transmitters to triangulate the location of the object. Thanks