Signals of Opportunity Aided Inertial Navigation

A signal of opportunity (SOP)-aided inertial navigation system (INS) framework is presented and studied. The following problem is studied. A mobile receiver with access to global navigation satellite system (GNSS) signals is aiding its onboard INS with GNSS pseudoranges. While navigating, the receiver draws pseudorange observations on ambient unknown terrestrial SOPs and estimates the SOPs’ states. GNSS signals become unavailable, at which point the receiver uses the SOPs to aid its INS. It is demonstrated that fusing SOP pseudoranges in a tightly-coupled GNSS-SOP-INS framework produces a superior navigation solution to a traditional tightly-coupled GNSS-INS framework. Moreover, in the absence of GNSS signals, it is demonstrated that aiding the INS via SOPs produces bounded estimation errors. The SOP-aided INS’s performance sensitivity is studied over varying quantity and quality of exploited SOPs. Experimental results are presented demonstrating a ground vehicle navigating exclusively with inertial measurement unit (IMU) data and pseudoranges from an unknown terrestrial SOP emanating from a cellular tower.