Principal Investigator


Prof. Toshiaki Tsuji(Aerospace Systems Engineering Group)

Japan Aerospace Exploration Agency(JAXA), Aviation Technology Directorate

Aviation Safety Innovation Hub, an honorary  member


Research Description

Satellite navigation (GNSS) is widely used with the U.S. GPS, but with the development of Russia's GLONASS, Europe's Galileo, and Japan's QZSS (Quasi-Zenith Satellite System), this field is expected to develop rapidly in the future.

In our laboratory, we are studying centimeter-level positioning and precise attitude estimation using GNSS, as well as navigation systems for manned and unmanned aircraft in combination with inertial navigation systems (INS). Recently, we have been working on a robust GNSS receiver augmented with INS to continue navigation in the presence of ionospheric anomalies and radio interference. We are also conducting research on technology to prevent aircraft accidents caused by turbulence and on guidance and control of unmanned aerial vehicles.


Recent Publications

  • Fujiwara, Tsujii, T., "GBAS Availability Assessment and Modeling of Ionospheric Scintillation Effects", NAVIGATION, Journal of The Institute of Navigation, Vol. 63, No. 4, Winter 2016, pp. 405-413.
  • Tsujii, T., Fujiwara, T., Kubota, T., "Improvement of INS-Aided GPS Tracking Performance under Strong Ionospheric Scintillation", NAVIGATION, Journal of The Institute of Navigation, Vol. 62, No. 2, Summer 2015, pp. 111-119.
  • T. Tsujii, T. Fujiwara, T. Kubota, Y. Kubo: Testing of an Ultra-tightly coupled GPS/INS under Strong Ionospheric Scintillation, Transactions of the Institute of Systems, Control and Information Engineers Vol.27, No.12, pp.476-485, 2014.
  • WANG, J., ALMAGBILE, A., WU, Y., & TSUJII, T., 2012. Correlation analysis for fault detection statistics in integrated GNSS/INS systems. Journal of Global Positioning Systems, Vol.11, No.2, pp.89-99, 2012.
  • T. Tsujii, T. Fujiwara, T. Kubota, C. Satirapod, P. Supnithi, T. Tsugawa, and H. K. Lee: Measurement and Simulation of Equatorial Ionospheric Plasma Bubbles to assess their impact on GNSS performance, Journal of Korean Society of Surveying, Geodesy, Photogrammetry and Cartography, Vol. 30, No. 6-2, pp.517-523, 2012.
  • J. Wang, A. Almagbile, Y. Wu and T. Tsujii: Correlation Analysis for Fault Detection Statistics in Integrated GNSS/INS Systems, Journal of Global Positioning Systems, Vol.11, No.2 (2012)
  • I. Petrovski and T. Tsujii: Digital Satellite Navigation and Geophysics: A Practical Guide with GNSS Signal Simulator and Receiver Laboratory(ケンブリッジ大学出版,2012)
  • T. Tsujii, T. Fujiwara, Y. Suganuma, H. Tomita, and I. Petrovski: Development of INS-Aided GPS Tracking Loop and Flight Test Evaluation, SICE Journal of Control, Measurement, and System Integration, Vol. 4, No. 1, pp. 015-021 (2011)
  • H-Y. Chen, S-B. Yu, H. Tung, T. Tsujii and M. Ando (2011): GPS Medium-Range Kinematic Positioning for the Seafloor Geodesy off-Eastern Taiwan, Engineering Journal, Chulalongkorn University, Vol 15, No 1(2011)
  • 杉本末雄,柴崎亮介編:GPSハンドブック(朝倉書店,2010)第10章「疑似衛星(スードライト)」執筆



  • 日本航空宇宙学会技術賞 2016.4
  • 科学技術分野の文部科学大臣表彰 科学技術賞(開発部門)2016.4
  • Best Paper Award of International Technical Conference on Circuits/Systems, Computer and Communications 2012 (ITC-CSCC 2012)2013.7


Academic Affiliations

  • The Japan Society for Aeronautical and Space Sciences(JSASS, 日本航空宇宙学会)
  • The Institute of Electronics, Information and Communication Engineers(IEICE, 電子情報通信学会)
  • The Institute of Positioning, Navigation and Timing of Japan(IPNTJ, 測位航法学会)
  • JSASS  Electronics and Information Systems Division Committee Member 2004.4 - 2006.3,2018.3 - Current
  • JSASS  Air Traffic Management (ATM) Division Committee Member 2014.4 - 2018.3
  • The Institute of Electrical Engineers of Japan(IEEJ, 電気学会) Research Committee for G-spatial Advancement by Positioning Member 2010.10 - Current
  • IPNTJ Satellite Positioning Engineer Certification Subcommittee Manager 2016.4 - 2019.2
  • 公益財団法人)航空輸送技術研究センター(ATEC) 「新たな進入・出発方式に関する調査・研究WG」委員 2013.4 - 2018.3
  • 一般財団法人)航空振興財団 航法小委員会 委員 2013.4 - 2018.3
  • Society for Advancement of Positionning Technologies(SAPT, 測位技術振興会) Vice President 2019.4 - Current


Joint Investigator 


  • Ken Fujiwara

   Japan Aerospace Exploration Agency(JAXA), Aviation Technology Directorate

   Aviation Safety Innovation Hub

  • Takehiro Yamamoto

   Japan Aerospace Exploration Agency(JAXA), Aviation Technology Directorate

   Aviation Safety Innovation Hub

  • Suguru Naruoka

   Japan Aerospace Exploration Agency(JAXA), Aviation Technology Directorate



  • Daiki Kawahara 
Topic Research on Error Reduction Using Dual Circularly Polarized Antennas During Satellite Tracking in Multipath Environments
    • Hiroaki Bonno
    Topic Research on Next-Generation Air Traffic Management Methods Considering a Conflict between Aircrafts

    • Maumu Yoneyama
    Topic The DOA Estimation and the Mitigation of Undesired Signals with GNSS Antenna Array


    • Yuto Takeuchi
    Topic Improving Attitude Estimation Accuracy Using Multi-Antenna GPS in Multipath Environments
      • Naoya Matsufuji
      Topic Doppler Navigation Using Low Earth Orbit (LEO) Satellites
          • Taisei Wakugawa
          Topic Research on improving the accuracy of GPS/INS integrated navigation using GPS signal weighting.
            • Naoto Yasugi 

            Topic Detection and removal of GNSS spoofing attacks on moving objects
              • Akiho Sema
              Topic Mutual Coupling Reduction Method for Improving GNSS Positioning Accuracy Using Array Antennas


              • Atsushi Osaka
              • Haruki Tanimura
              • Akito Kitamura
              • Kouta Ikeno


              • Kento Shiokawa


              Exploration of Potential Routes for Low-Altitude UAM Operation near Kansai International Airport 
              • Riku Awai
              Topic GNSS Adaptive Beamforming Including Null-steering for Unwanted Signal

              • Yuki Ono
              Topic Reducing Initial Convergence Time of Precise Point Positioning by Triple-Frequency Ambiguity Resolution

              • Shimpei Tanaka
              Topic Development of a Model to Detect GNSS Reflected Signals Using Machine Learning and Application to Positioning

              • Shuki Yoshida
              Topic GNSS Multipath Error Mitigation Using Dual-Polarization Antenna

              • Hiroko Sakakura
              Topic Estimation of Earth’s Surface Characteristics by GNSS Reflectometry Using a Dual-Polarization Antenna

              • Junnosuke Shibata
              Topic DOA Estimation of GNSS Signals Using an Array Antenna for Anti-Spoofing


              • Toshinori Mori
              Topic Effect of Air Traffic Flow Management and Point Merge System on Air Traffic Flow


              • Kensuke Eguchi
              Topic Fast attitude determination of small flying vehicle using multi-antenna GPS 


              • Yumeko Kawabata
              Topic Development of a Model to Detect GNSS Reflected Signals by Using Doppler Frequency and its Application to Kinematic Positioning 


              • Daigo Iki
              Topic Simulation to Examine the Positioning Feasibility by Combining the Quasi-Zenith Satellite System (QZSS) and Low Earth Orbit (LEO) Satellite Constellation

              • Ryo Yama
              Topic Evaluation of Mobile Positioning Accuracy Using Multi-GNSS/INS Integrated Navigation

              • Yuki Akizuki
              Topic Improvement of positioning accuracy through weighting based on the type of GPS signals

              • Hideto Shiotani
              Topic The research on GNSS spoofing detection Using IMU integration


              Reliability Assessment of Flight Data in Small Aircraft Using Smartphones

              • Yoshiki Nakase
              Topic Research on the observation of ionospheric plasma bubbles using low earth orbit satellites

              • Yoshihiro Yamauchi
              Topic Improvement of PPP performance by detecting, estimating and removing GNSS cycle slips

              Past Topic Analysis of Loosely Coupled PPP/INS Integrated Navigation

              • Kouki Matsumoto
              Topic Deriving the Protection Level of an Automobile Running in a Multipath Environment.