Signal fault detection for global navigation satellite system using multiple antennas

A system for providing Global Navigation Satellite System (GNSS) based navigation solutions including attitude and heading with signal fault detection, the system comprising:

• a plurality of antennas configured to receive a plurality of the satellite signals;
• and
• a system controller configured to,
• determine at least a true carrier phase measurement for each received satellite signal and antenna,
• implement a first estimator to form a first navigation solution estimate based at least in part on determined true carrier phase measurement differences obtained from measured satellite signals across the plurality of antennas,
• implement a solution separation function that repeatedly includes,
• removing all satellite signals associated with a select satellite,
• determining true carrier phase measurements from the remaining satellite signals,
• implementing a second estimator to form a second navigation solution estimate based at least in part on determined true carrier phase measurement differences obtained from measured satellite signals across the plurality of antennas from the remaining satellite signals,
• using estimated states of receiver clock differences when different GNSS receivers are used in tracking the satellite signals for each antenna in calculating the first and second navigation solution estimate, and
• detecting a fault in the satellite signals if a magnitude of a difference between the at least one of the first navigation solution variables and the at least one of the second navigation solution variables exceeds a threshold.

A method of providing Global Navigation Satellite System (GNSS) based attitude and heading with signal fault detection, the method comprising:

• receiving a plurality of satellite signals from a plurality of satellites at a plurality of antennas;
• determining a true carrier phase measurement for each received satellite signal;
• for at least one satellite signal from a satellite, resolving integer ambiguities in true carrier phase measurement differences for a pair of antennas across a plurality of pairs of antennas to obtain a first set of resolved integer ambiguity measurements;
• calculating at least one of a first attitude and a first heading based on the first set of resolved integer ambiguity measurements;
• and
• applying a solution separation that repeatedly includes,
• removing all satellite signals associated with a select satellite of the plurality of satellites,
• for at least one satellite signal from the remaining satellites, resolving integer ambiguities in true carrier phase measurement differences for a pair of antennas across a plurality of pairs of antennas to obtain at least one second set of resolved integer ambiguity measurements,
• calculating at least one of a second attitude and a second heading based on the at least one second set of resolved integer ambiguity measurements,
• determining a difference between the calculated at least one of the second attitude and the second heading to the calculated at least one of the first attitude and the first heading, and
• detecting a fault in the satellite signals when the determined difference exceeds a defined threshold.