awblain
Hopefully... but it wouldn't have the time of flight measured for a call and reply signal, so the location might not be up to much.
But they wouldn't need the return path time (I think that is what you meant).
If they had the Inmarsat ping, and another satellite in a different orbit recorded the same ping, that would help.
From the Inmarsat data they would have the absolute time the ping was sent. They would have the time the 2nd satellite detected the ping. They could then calculate distance from this 2nd satellite (which would be at a known location at this known time).
That would give them 3 spheres with which to work - known distance from Inmarsat, known distance from 2nd satellite, and surface of earth.