| GPS Multipath is caused by reflections of the signal from nearby surfaces and produces significant errors in both the GPS pseudorange and the carrier phase. In this research, algorithms are developed to reduce multipath found in the GPS carrier phase measurement. Multipath errors are estimated using a spatial SNR-based mitigation technique, as well as a spatial phase-based method. Once the errors have been identified, corrections are applied to both simulated and real data in order to assess the phase improvement. Unfortunately, the method is not effective in identifying a reflector capable of removing multipath in the flight data from CRISTA-SPAS. However, the results using ground data display improvements in the RMS of the residuals of up to 22 percent, and indicate further potential for multipath reduction capabilities using the reflector identification algorithm. |
