Improvement of INS-Aided GPS Tracking Performance under Strong Ionospheric Scintillation

Ionospheric anomaly is one of the major error sources which affect the UPS performance. Especially, ionospheric scintillation may cause UPS signal loss, and multiple losses would degrade the availability of positioning/navigation service (e.g. GBAS). In order to improve tracking performance under scintillation, an INS-aided tracking loop has been developed, and flight tests were conducted at around Ishigaki-Island where ionosphere scintillation occurs frequently. Evaluations of phase tracking performance were carried out off-line by using a software-defined UPS receiver which processes stored IF data. As results, continuous phase tracking under strong scintillation was demonstrated by the INS-aided tracking loop.