Page 9 - 卫星导航2021年第1-2合期

Volume 2, Issue 1-2, July 2021 Research Summary

Multi-sensor integrated navigation
Precise Point Positioning (PPP) has been demonstrated as an effective tool in high-precision
positioning and shows the advantages of efficiency and flexibility compared to the baseline network
approach. However, the reliability and availability of PPP will be significantly degraded in the
extremely difficult conditions where Global Navigation Satellite System (GNSS) signals are blocked
frequently. The authors integrated the Visual-Inertial Navigation Systems (VINS) with multi-GNSS
PPP to ameliorate such conditions. The authors presented a graph-optimization based and semi-tight
coupling framework of multi-GNSS PPP and Stereo VINS (S-VINS), which achieves the bidirectional
location transfer and sharing in two separate navigation systems. The authors assessed the positioning
performance of the S-VINS aided PPP solution and the semi-tightly coupled multi-GNSS PPP/
S-VINS solution in GNSS-challenged environments. They proved that the positioning performance
of the PPP solution can be significantly improved with the aiding of S-VINS. Meanwhile, the multi-
GNSS PPP/S-VINS solution realizes a higher positioning accuracy and availability compared with the
multi-GNSS PPP/INS solutions in GNSS-challenged environments, which shows a great potential of
the multi-sensor fusion system for precise positioning.
Related article: Semi-tightly coupled integration of multi-GNSS PPP and S-VINS for precise
positioning in GNSS-challenged environments (doi: 10.1186/ s43020-020-00033-9)

A novel signal authentication technique
Civil receivers of Global Navigation Satellite System (GNSS) are vulnerable to spoofing and jamming
attacks due to their signal structures. The Spreading Code Authentication (SCA) technique is one
of the GNSS message encryption identity authentication techniques. A commonly used spreading
code authentication technique inserts unpredictable chips into the public spreading code. This
method changes the signal structure, degrades the correlation of the spreading code, and causes
performance loss. This work proposes a binary phase hopping based spreading code authentication
technique, which can achieve identity authentication without changing the existing signal structure.
Analysis shows that this method can reduce the performance loss of the original signal and has good
compatibility with the existing receiver architecture.
Related article: Binary phase hopping based spreading code authentication technique (doi:
10.1186/ s43020-021-00037-z)