Performance Analysis of Opportunistic ARAIM for Navigation With GNSS Signals Fused With Terrestrial Signals of Opportunity

Integrity monitoring of a vehicular navigation system that utilizes multi-constellation global navigation satellite systems (GNSS) signals fused with terrestrial signals of opportunity (SOPs) is considered. An opportunistic advanced receiver autonomous integrity monitoring (OARAIM) framework is developed to detect faults and calculate protection levels (PLs). The influence of fusing SOPs on the integrity performance is analyzed. It is shown that fusing a single SOP with GNSS signals essentially increases both the horizontal PL (HPL) and vertical PL (VPL), while fusing two or more SOPs could reduce the PLs and improves fault detection. Performance sensitivity analysis for the probability of SOP fault and user range error is conducted to characterize the fault-free HPL under different regimes. Experimental results on an unmanned aerial vehicle (UAV) navigating with GPS signals fused with cellular SOPs are presented to validate the effectiveness of the OARAIM framework and demonstrate the analysis of the integrity performance in the horizontal direction.