Fast location surveying algorithm to support the deployment of mobile DGNSS

Abstract

Differential Global Navigation Satellite Systems (DGNSS) are one of the methods of providing high accuracy, integrity, continuity, and availability navigation information to users who are carrying out outdoor missions. Standalone GNSS can provide unreliable navigation information due to possible system component failures or environmental anomalies. DGNSS can not only amalgamate these anomalies, but also monitor the integrity of the system using reference stations that have known exact positions. However, in foreign environments, geographically fixed reference stations are rarely available. Therefore, to provide DGNSS service in these areas, the concept of Mobile DGNSS was proposed. The proposed system uses mobile vehicles to serve as reference stations, which grants the stations both mobility and deployability. Effectively, the stations can site themselves in unknown environments to provide DGNSS service, and some of the stations can reposition themselves if the mission requirements change. One of the challenges for the implementation of Mobile DGNSS is its system deployment time. If the system is to be used in situations such as providing aid in disaster sites, the deployment time should be minimized. As DGNSS uses accurate surveyed positions of the reference stations to provide correction and integrity navigation information to the users, the surveyed positions’ errors degrade the overall system performance. Thus, in this thesis, a method to reach specific surveyed position accuracies in a shorter amount of time is proposed to reduce the total system deployment time. Overall, two algorithms are proposed to reduce the deployment time. The algorithms utilize accurate relative distances between the stations to improve the accuracy of the surveyed positions. Furthermore, in order to test the effectiveness of the algorithms, a relationship between the surveyed position errors and the total system performance is established. The contents of this research are expected to assist in the realization of an actual Mobile DGNSS.