Flight Evaluations of INS-Aided GPS Performance under Strong Ionospheric Scintillation

Toshiaki Tsujii, Takeshi Fujiwara, and Yusuke Shimizu

Abstract:	Ionospheric anomalies are major error sources that affect the performance of the GPS (Global Positioning System). In particular, ionospheric scintillation may cause GPS satellite signal loss, and multiple losses can degrade the availability of positioning/navigation services such as GBAS (Ground-Based Augmentation Systems). In order to improve the tracking performance of GPS receivers under scintillation conditions, a tracking loop aided by INS (Inertial Navigation System) has been developed, and flight tests to evaluate it were conducted around the island of Ishigaki where ionosphere scintillation frequently occurs. Phase tracking performance evaluation was carried out off-line using a software-defined GPS receiver which processes stored IF (Intermediate Frequency) data. The use of INS enabled a longer integration time of GPS signals, which increased the signal-to-noise ratio (SNR). As a result, the INS-aided tracking loop achieved continuous phase tracking even under strong scintillation conditions. However, although tracking was possible without cycle slips, the range accuracy would be degraded. In this paper, the positioning accuracy is evaluated under strong scintillation conditions where the tracking with a long integration time (up to 100ms) is applied.
Published in:	Proceedings of the ION 2015 Pacific PNT Meeting April 20 - 23, 2015 Marriott Waikiki Beach Resort & Spa Honolulu, Hawaii
Pages:	1043 - 1050
Cite this article:	Tsujii, Toshiaki, Fujiwara, Takeshi, Shimizu, Yusuke, "Flight Evaluations of INS-Aided GPS Performance under Strong Ionospheric Scintillation," Proceedings of the ION 2015 Pacific PNT Meeting, Honolulu, Hawaii, April 2015, pp. 1043-1050.
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