I would like to determine with high accuracy the relative distances between three RF transmitters a few meters apart by analysis of phase interference in the received wave, the receiver being at an undefined distance a few hundred meters away. Is there a simple method for this? The three RF transmitters can be arranged to transmit the same phase and frequency, or differing frequencies, whatever is required. Is there some kind of radar or reflection interferometry technique that exists and provides the information required, from reflectors?
Check this out, it does calculate the similarities of 2 or more signals http://www.mathworks.com/help/signal/examples/measuring-signal-similarities.html