Evaluation of Radiation Tolerance of Redundant GNSS Module System for Space Applications

Shuichi Matsumoto, Tomonori Ichikawa and Tomohiko Sakai

Abstract:	GNSS navigation has become essential for most of space applications in low Earth orbit and one of the issues is that conventional GNSS receivers for space applications are expensive due to the use of space-qualified parts. One approach to reduce the cost of GNSS receivers is to use non-space electronic parts configured redundantly with special radiation mitigation techniques. We have developed a triple-redundant GNSS module system using commercial single-output GNSS modules (RGNSS-S) for launch vehicles. RGNSS-S detects the single-event effect (SEE) errors, isolates the incorrect GNSS module, and continues outputting correct GNSS navigation results. We conducted radiation tests to evaluate the radiation error probability of the commercial single-output GNSS modules and evaluated the on-orbit radiation error probability of RGNSSS from the results of the radiation tests. We also conducted the flight tests of RGNSS-S during the launch and on-orbit phases of the H3 launch vehicle and confirmed that RGNSS-S performed well and that its navigation accuracy is as expected during the launch phase and on-orbit phase. As the next step, we have been developing a dual-output GNSS module (DoGnss module) and a redundant GNSS module system using DoGnss modules (RGNSS-D). The hardware of the DoGnss module is based on the a commercial GNSS modules who incorporates two independent GNSS chips, RGNSS-D has lockstep functions on GNSS navigation as well as a voting function of multiple GNSS navigation solutions. This paper presents the system design of RGNSS-S, radiation test results of the commercial single-output GNSS modules used in RGNSS-S, the radiation error probability of RGNSS-S, and its flight test results. This paper also describes the system design and the radiation test results of the DoGnss module and the RGNSS-D. Finaly, this paper concludes the feasibility of a redundant GNSS module system using commercial GNSS modules for the orbital radiation environment.
Published in:	Proceedings of the 38th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2025) September 8 - 12, 2025 Hilton Baltimore Inner Harbor Baltimore, Maryland
Pages:	689 - 702
Cite this article:	Matsumoto, Shuichi, Ichikawa, Tomonori, Sakai, Tomohiko, "Evaluation of Radiation Tolerance of Redundant GNSS Module System for Space Applications," Proceedings of the 38th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2025), Baltimore, Maryland, September 2025, pp. 689-702. https://doi.org/10.33012/2025.20314
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