Carrier Phase Double Differencing GNSS Receiving System with Spatial Integrity Monitoring

A system for determining a reference receiver for carrier phase differencing in a global navigation satellite system (GNSS), comprising:

• a set of antennas of a set of receivers configured to receive measurements from at least five satellites, wherein the set of antennas are arranged at fixed locations on a moving object;
• a processor configured to apply right-hand circular polarization (RHCP) at a first subset of antennas of a first subset of receivers and left-hand circular polarization (LHCP) at a second subset of the antennas of a second subset of receivers to produce first and second phase lock loop (PLL) outputs, and to apply line-of-sight (LOS) and non-line-of-sight (nLOS) detection to the first and second PLL outputs to indicate a presence of multipath, and to output whether or not the first subset of receivers are affected by multipath and polarization changing impairments, and to perform carrier phase double differencing using carrier phase measurements to indicate which receiver is used as a reference receiver for the carrier phase double differencing.