TCAS position

[divinehover]

Good day all

How does TCAS determine the position of another a/c? I assume it uses doppler for range but position (bearing) is a bit of a mystery to me. Could it be phase differential like VOR.

[Background Noise]

Directional antenna for azimuth, interrogation/response time for distance and mode C for vertical position/relative height.

[gearpins]

hi,
thereh is another thread "OEI TCAS" which adress tcas in toto (hyperlink).just a couple of days old hope its helpful