Performance Analysis of Using the Next generation Australian SBAS with Precise Point Positioning Capability For Intelligent Transport Systems

Abstract

In 2018, a next-generation Satellite-Based Augmentation System (SBAS) test-bed was launched in Australia/New-Zealand in preparation for building an operational system. This new generation SBAS includes L1 legacy SBAS, new dual-frequency multi-constellation (DFMC) SBAS, and orbit and clock corrections for precise point positioning (PPP) using GPS and Galileo. In this paper, the next generation SBAS and its models are first presented, and the benefits of using its new components are discussed. Test results for lane identification applications in Intelligent Transport Systems (ITS) are presented and analyzed. Kinematic tests were performed in different ITS environments. These are characterized by different levels of sky-visibility and multipath, including clear sky, suburban, low-density urban, and high-density urban environments. Performance analysis show that results vary widely depending on the operational conditions but all SBAS solutions have better positioning accuracy compared with the standalone solutions that are currently used in transport applications. The DFMC SBAS slightly outperformed the L1 SBAS, with accuracy at submeter, and it has advantages during periods of fluctuations of the ionosphere with an extended coverage area. As expected, the SBAS-based PPP solutions have shown to give the best positioning precision and accuracy among all tested solution types, with sub-decimeter level accuracy, provided that enough convergence time is available. The paper concluded by giving remarks on the use of this new technology for ITS.

Reliable Positioning and Journey Planning for Intelligent Transport Systems

“…Figure 9 shows two examples of applying the new generation DFMC and floatambiguity PPP SBAS in the open-sky (left panel) and semi-urban (right panel) environments. Analysis of results shows that the new SBAS DFMC solutions have slightly better accuracy than the SBAS L1 solutions, but both generate errors between sub-m to more than 2 m. In addition, the multi-constellation PPP solutions have shown to provide the best positioning precision and accuracy among all the tested solution types (L1 SBAS, DFMC SBAS, and SBAS-based PPP) with subdecimeter level standard deviations after solution convergence [35], provided that enough convergence time is available, which may take up to 30 min. Testing clearly demonstrates that positioning performance of both DFMC SBAS and PPP methods is strongly dependent on the environment of the application, which is linked to the strength of the satellite geometry, number of observed satellites, the presence of multipath and NLOS.…”