Given the number of incidents related to freezing pitot tubes, is there any current/planned implementation to infer aircraft position/speed/attitude/bearing based on TCAS data as a last resort data point? If not, is this at least doable?
Even if TCAS gives only relative data, one may correlate the data at the last moment before pitot data are lost to assist in dead reckoning.
Edit: I am not sure if my question has been misunderstood, or that I am misinterpreting the answers. The question is more like inferring current aircraft's data from transponders of surrounding aircrafts. Let's suppose at time $t_1$ I have planes A, B, and C within my TCAS range. I will possess information regarding their bearing, distance, speed, and altitude. At time $t_2$, even without my own altimeter, I can at least infer my own vertical speed using trigonometry. A, B, C are like ocean currents, a background moving together with me. If I know enough information about them, depending on what TCAS's underlying data stream provides, I can probably infer my own position, altitude, speed, and heading. From my limited understanding, TCAS bearing, distance, and speed are relative to me. However if I have not mistaken, despite what is shown on the screen, altitude is absolute measurement from the other planes' altimeter. One side fixed on a similar triangle, you'll get the rest.