The GPSP is a tracking system that uses the GPS constellation of satellites to determine the exact position of a transmitter.
The GPSP supports precise orbit determination by the DORIS system. It also helps to improve gravity field models and provides data for satellite positioning accurate to about 50 metres and 50 nanoseconds.
The GPSP receives dual-frequency navigation signals continuously and simultaneously from 16 GPS satellites. It uses these signals to acquire phase measurements accurate to about one millimetre and pseudo-range measurements accurate to about 10 centimetres.
The onboard system consists of two independent receivers operating in cold redundancy, each with an omnidirectional antenna, low-noise amplifier, quartz oscillator, sampling converter and a baseband digital processor communicating via the bus interface.