Electronic Navigation Research Institute Research Articles

国立研究開発法人電子航法研究所(教育・研究機関紹介)

国立研究開発法人電子航法研究所(教育・研究機関紹介)

運輸省電子航法研究所電子航法開発部航法システム研究室(国内,ラボラトリーズ)

運輸省電子航法研究所電子航法開発部航法システム研究室(国内,ラボラトリーズ)

電子航法研究所の研究,開発 : その変遷と長期ビジョン( 国産飛行機初飛行から100年,日本の航空のこれまでとこれから 第4回)

電子航法研究所の研究,開発 : その変遷と長期ビジョン( 国産飛行機初飛行から100年,日本の航空のこれまでとこれから 第4回)

電離層シンチレーションの影響下におけるGPS受信機の性能評価

Ionospheric scintillation induces a rapid change in the amplitude and phase of radio wave signals. This is due to irregularities of electron density in the F-region of the ionosphere. It reduces the accuracy of both pseudorange and carrier phase measurements in GPS/Satellite Based Augmentation System (SBAS) receivers and can cause loss of lock on the satellite signal. Scintillation is not strong at mid-latitude regions, but severe effects occur mainly in a band approximately 15-degree latitude on either side of the magnetic equator and sometimes in the polar and auroral regions. Most scintillation occurs for a few hours after sunset during the peak years of the solar cycle. In Japan, several ionospheric scintillations were observed by Electronic Navigation Research Institute (ENRI). This work intended to investigate the scintillation characteristics in Japan and statistically evaluate constant bandwidth phase locked loop (PLL) and a Fast Adaptive Bandwidth (FAB) PLL performance under the ionospheric scintillation condition. The results show that the characteristics are consistent with the models proposed in early studies and the FAB PLL has the flexibility against the scintillation effects compared with the constant PLL.

Observations of Ionospheric Scintillation on GPS Signals in Japan

: Ionospheric scintillation is the rapid amplitude and phase fluctuation of transionosphere radio waves due to local irregularity of the ionosphere. At low magnetic latitudes, amplitude scintillation often occurs after sunset around equinox periods, especially in the maximum of solar activity. GPS signal fading due to scintillation can cause receiver loss of lock. To assess the effect of ionospheric scintillation on the MTSAT Satellite-based Augmentation System (MSAS), the Electronic Navigation Research Institute (ENRI) has conducted observations of ionospheric scintillation since March 1999. Strong scintillation has been observed, some of which continued over 10 min with an elevation mask of 15 deg. The number of satellites tracked by the receiver decreased distinctly by 1–4 for about 3 h when strong scintillation occurred. This result indicates that ionospheric scintillation has the potential to affect GPS and must be taken into account for satellite-based augmentation system (SBAS) operation in the area near the magnetic equator.

106 将来的な航空管制シミュレーションと仮想現実空間の連接手法に関して

Electronic Navigation Research Institute (ENRI) had started to construct a total air traffic control (ATC) simulation facility in 1993. An airport tower ATC simulator and a flight simulator have been developed and ENRI is now carrying out several experiments and simulation. In this paper, a coupling method of three or more virtual reality spaces for creating a larger ATC simulator is mentioned and some basic ideas of the coupling method are also explained.