Demonstration of Radio SLAM with Terrestrial Signals of Opportunity in a GPS-Denied Environment

Radio simultaneous localization and mapping (SLAM) with terrestrial signals of opportunity (SOPs) in a real-world GPS-denied environment is demonstrated. First, radio SLAM with known and unknown SOP maps is formulated. In the former case, the receiver's spatial states are estimated alongside the receiver-SOPs temporal states; while in the latter, the receiver's and SOPs' spatial states are estimated alongside the receiver-SOPs temporal states. Next, experimental results are presented of a vehicle navigating at Edwards Air Force Base, California, USA, while GPS signals were under intentional jamming. The vehicle exploited 7 terrestrial cellular SOP transmitters in the environment to navigate for 5 km in 180 seconds, with one of the SOPs more than 25 km away. Monte Carlo radio SLAM results with various levels of SOP position uncertainty are presented, from fully-known to poorly-known with 95% uncertainty ellipses of radii 7.8 m, 24.5 m, 77.4 m, and 245 m, achieving a 2D position position root-mean squared error (RMSE) of 2.6 m, 16.8, 23.6, 39.4 m, and 44.3 m, respectively.