Research

Research

PPP

Precise Point Positioning (PPP) is a GNSS-based positioning method. It is a positioning technology that uses precise satellite orbit and clock error information to achieve centimeter-level positioning accuracy using only a single receiver. Since PPP does not require a ground reference station, it is expected to be used in many fields because of its ability to provide highly accurate positioning regardless of location.

Therefore, this laboratory is working on centimeter-class positioning of aircraft using PPP technology.

comparison_PPP_and_RTK-GPS

Fig1　Comparison of PPP and RTK-GPS

GNSS/INS Integrated Navigation

Satellite navigation (GNSS) is widely used as a system that enables easy and convenient positioning anytime, anywhere. However, due to the weakness of its radio waves, there is always concern about the vulnerability of the system in environments with multiple propagation (multipath), ionospheric anomalies, radio interference, etc.

Therefore, we will conduct research and development of robust navigation technology that is combined with an inertial navigation system (INS) that does not rely on radio waves, and that has a satellite selection/elimination function using an array antenna with multiple elements.

airport-EM-environment_reliability-enhancement_by_GNSS-INS

Fig2　 Radio Environment on Airport Surfaces and GNSS/INS for Reliable Navigation

Array Antenna

An array antenna can control its pattern by adjusting the amplitude and phase of multiple antenna elements.

antenna-pattern

Fig3　Directivity Pattern of  an Array Antenna

Research on GNSS Reflected Waves

Air Traffic Management(ATM)

The Global air traffic volume is expected to increase significantly in the future, and the accompanying decline in operational efficiency and increased burden on air traffic controllers are future issues. A new air traffic control system that provides time control for aircraft in cruise is being considered as one means of resolving these issues. On the other hand, a conflict between aircrafts must be avoided at the point of  safety. Therefore, it is necessary to evaluate the usefulness of the new system in consideration of the effects of a conflict in order to apply it to actual operations. 

Therefore, this laboratory is investigating the optimal route design method to avoid a conflict between aircrafts for the evaluation.

Publications and Presentations

  • A. Sema, The Institute of Positioning, Navigation and Timing of Japan, GPS/GNSS Symposium2023, 2023.10.25-27, Tokyo, Japan(2023)　（ポスターセッション最優秀ポスター発表賞受賞）
  • N. Yasugi, The Institute of Positioning, Navigation and Timing of Japan, GPS/GNSS Symposium2023, 2023.10.25-27, Tokyo, Japan(2023)　（ポスターセッション優秀ポスター発表賞受賞）
  • K. Ikeno, H. Tanimura, A. Kitamura, A.Osaka and T.Tsujii, The Institute of Positioning, Navigation and Timing of Japan, GPS/GNSS Symposium2023, 2023.10.25-27, Tokyo, Japan(2023)　（高精度測位チャレンジ3位入賞）
  • D. Kawahara and T. Tsujii, The Institute of Positioning, Navigation and Timing of Japan, GPS/GNSS Symposium2023, 2023.10.25-27, Tokyo, Japan(2023)　（SDRコンテスト2位受賞）
  • M. Yoneyama and T. Tsujii, A Study on GNSS Multipath Arrival Direction Estimation and Error Reduction Using Antenna Array, The Institute of Positioning, Navigation and Timing of Japan, National Convention, 2023.5.17-19, Tokyo, Japan(2023)　（学生最優秀研究発表賞受賞）
  • H. Shiotani and T. Tsujii, The research on GNSS spoofing detection using IMU,  The 60th Aircraft Symposium, 2022.10.11-13, Niigata, Japan(2022)　　（学生優秀講演賞受賞）
  • J. Shibata and  T. Tsujii, K. Goto, S. Ohsawa,DOA Estimation of GNSS Signals for Spoofing Detection Based on the MUSIC Algorithm, Aerospace Technology Japan Vol.70,  No.5, October 2022, 137-145.
  • M. Yoneyama and T. Tsujii, A Study on GNSS Multipath Arrival Direction Estimation and Error Reduction Using Antenna Array, The Institute of Positioning, Navigation and Timing of Japan, National Convention, 2022.6.8-10, Online　（学生最優秀研究発表賞受賞）
  • M. Awai and  T. Tsujii, T. Fujiwara, S. Ohsawa,GNSS Adaptive Beamforming Including Null-steeringfor UnwantedSignal, Aerospace Technology Japan Vol.69,  No.3, 2021, 122-127.
  • S. Tanaka and T. Tsujii,Development of a Model to Detect GNSS Reflected Signals Using Machine Learning and Application to Positioning , Aerospace Technology Japan Vol.69,  No.6, 2021, 229-235.
  • Y. Kawabata and T. Tsujii, Development of Reflected-Signal Detection Methods to Improve GNSS Kinematic Positioning Accuracy Under Urban Environments, The 59th Aircraft Symposium, 2021.11.30-12.2, Online(2021）　（学生優秀講演賞受賞）
  • Y. Akizuki, 都市部におけるTightly-coupled方式を用いた GNSS/INS複合航法の測位精度の評価, GPS/GNSS Symposium 2021, Beginers' Session, 2021.10.27-29, Online(2021)　（研究奨励賞受賞）
  • H. Shiotani and T. Tsujii, Research on Improving the Accuracy of Indoor Positioning Using Smartphones, GPS/GNSS Symposium 2021, Beginers' Session, 2021.10.27-29, Online(2021)　（研究奨励賞受賞）
  • J. Shibata, A Study on Signal Arrival Direction Estimation Using Array Antenna for Anti-Spoofing, The Institute of Positioning, Navigation and Timing of Japan, National Convention, 2021.6.23-25, Online　（学生最優秀研究発表賞受賞）
  • T. Mori and T. Tsujii, Effect of Enroute Time Management on Flight Trajectories in the Terminal Area, Transactions of the Japan Society for Aeronautical and Space Scinences, Aerospace Technology Japan Vol.19,  No.6, November 2021, 813-820.
  • T. Tsujii, K. Yonebayashi, T. Fujiwara and S. Ohsawa, GNSS Array Antenna for Mitigating Multipath Errors in Urban Environment, International Symposium on GNSS 2018, Bali, Indonesia, Nobember 21-23, 2018.
  • K. Yonebayashi, K. Fujiwara, S. Osawa and T. Tsujii, CRPA技術による衛星航法のマルチパス誤差低減、The 56th Aircraft Symposium, 2018.11.14-16, Yamagata, Japan（2018）
  • K. Yonebayashi, K. Fujiwara, S. Osawa and T. Tsujii, Hardware bias calibration for CRPA by using carrier phase measurement, GPS/GNSS Symposium 2018, 10.30-11.1, Tokyo, Japan(2018）　（学生最優秀研究発表賞受賞）
  • K. Yonebayashi, K. Fujiwara, S. Osawa and T. Tsujii, GNSSアレーアンテナのハードウェアバイアス較正に関する研究, The Institute of Positioning, Navigation and Timing of Japan, National Convention, 2018.5.16-18, Tokyo, Japan（2018）
  • H. Ninomiya, T. Tsujii, T. Fujiwara and Y. Shimizu, Precise point positioning for aircraft using QZSS augmentation signal, International Symposium on GNSS 2017, 10-13 December, 2017, Hong Kong, China
  • M. Ninomiya, T. Tsujii, K. Fujiwara and Y. Shimizu, 準天頂衛星の補強信号を利用した航空機の精密単独測位に関する研究, The 55th Aircraft Symposium, 2017.11.20-22, Shimane, Japan(2017)
  • K. Yonebayashi, GNSSマルチパス誤差軽減のためのアレーアンテナに関する実験的研究, The 55th Aircraft Symposium, 2017.11.20-22, Shimane, Japan(2017)
  • M. Ninomiya, T. Tsujii, K. Fujiwara and Y. Shimizu,  QZSS補強信号を利用した精密単独測位法による航空機の位置推定, GPS/GNSS Symposium 2017, 2017.11.7-9, Tokyo, Japan(2017)
  • K. Yonebayashi, T. Tsujii, K. Fujiwara and Y. Shimizu, ソフトウェア受信機によるGNSSアレーアンテナの指向性操作に関する研究, GPS/GNSS Symposium 2017, 2017.11.7-9, Tokyo, Japan(2017)　(最優秀学生発表賞（ポスター部門）)