Question id 281 - Radio Navigation - ATPL - Airline Transport Pilot license

Measuring the time taken for a minimum number of satellites' transmissions, in known positions, to reach the aircraft's receiver
Measuring the pulse lengths of signals received from a minimum number of satellites received in a specific sequential order
Measuring the time taken for an aircraft's transmissions to travel to a number of satellites, in known positions, and return to the aircraft's receiver
Inhibit unwanted ground returns