Pedestrian Heading Bias Correction using Low Earth Orbit Signals of Opportunity

This paper describes a method for utilizing low Earth orbit (LEO) satellites as signals of opportunity (SOP) to obtain a course measurement that is used to correct a static heading bias due to sensor misalignment in a pedestrian dead reckoning (PDR) system. This is accomplished using non-cooperative Doppler shift measurements from LEO satellites batched over time to produce course measurements for a moving pedestrian. These course measurements are used to correct the heading bias experienced in many PDR inertial navigation systems (INS). This methodology was validated using Monte Carlo simulation studies in a variety of different testing scenarios. Under nominal noise conditions, the heading bias is corrected to within a few degrees with LEO aiding. This heading correction greatly improves the navigation system’s position solution. The algorithm also performs well with many different satellite geometries and update rates, proving its usefulness for a wide variety of LEO satellite systems. However, the quality of the heading estimation is directly proportional to the noise on the input heading measurements.