GPS system and method for deriving pointing or attitude from a single GPS receiver

摘要

A GPS single-receiver pointing/attitude system derives pointing/attitude measurements by correlating a selected GPS code (either P or C/A), recovered from GPS navigation signals using a single GPS receiver with multiple GPS antennas (a reference antenna and at least two slave antennas for pointing or three for attitude). For a two antenna pointing application, the GPS receiver (FIG. 4) includes, for each receiver channel, the incoming GPS signals are applied to three code correlators (72-75) assigned to the reference antenna, and three code correlators (76-77) assigned to the slave antenna, which provide corresponding reference and slave I and Q correlation outputs. The single- receiver pointing technique involves: (a) using the reference I and Q correlation outputs to establish a conventional reference antenna tracking loop; and (b) processing the reference and slave I and Q correlation outputs (using differential carrier doppler phase or code phase measurements) to determine phase differences from which pointing can be computed.