Flight Test Result for the Ground-Based Radio Navigation System Sensor with an Unmanned Air Vehicle

Sensors

Jaegyu Jang¹  Woo-Guen Ahn²  Seungwoo Seo²  Jang Yong Lee²  Jun-Pyo Park² 

[1] The 3rd R&D Institute-4, Agency for Defense Development, Yuseong P.O. Box 35, Daejeon 305-600, Korea;

关键词: pseudolite;    pulsed signal;    false lock;   

DOI  :  10.3390/s151128472

来源: mdpi

【 摘 要 】

The Ground-based Radio Navigation System (GRNS) is an alternative/backup navigation system based on time synchronized pseudolites. It has been studied for some years due to the potential vulnerability issue of satellite navigation systems (e.g., GPS or Galileo). In the framework of our study, a periodic pulsed sequence was used instead of the randomized pulse sequence recommended as the RTCM (radio technical commission for maritime services) SC (special committee)-104 pseudolite signal, as a randomized pulse sequence with a long dwell time is not suitable for applications requiring high dynamics. This paper introduces a mathematical model of the post-correlation output in a navigation sensor, showing that the aliasing caused by the additional frequency term of a periodic pulsed signal leads to a false lock (i.e., Doppler frequency bias) during the signal acquisition process or in the carrier tracking loop of the navigation sensor. We suggest algorithms to resolve the frequency false lock issue in this paper, relying on the use of a multi-correlator. A flight test with an unmanned helicopter was conducted to verify the implemented navigation sensor. The results of this analysis show that there were no false locks during the flight test and that outliers stem from bad dilution of precision (DOP) or fluctuations in the received signal quality.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.