Borio Daniele, Gioia Ciro
European Commission, Joint Research Centre (JRC), Institute for the Protection and Security of the Citizen (IPSC), Security Technology Assessment Unit, Via Enrico Fermi 2749, 21027 Ispra (VA), Italy.
Piksel Ltd Italian Branch, Via Ernesto Breda 176, 20126 Milano (MI), Italy.
Sensors (Basel). 2016 Jan 16;16(1):111. doi: 10.3390/s16010111.
A global navigation satellite system (GNSS)-based navigation is a challenging task in a signal-degraded environments where GNSS signals are distorted by multipath and attenuated by fading effects: the navigation solution may be inaccurate or unavailable. A possible approach to improve accuracy and availability is the joint use of measurements from different GNSSs and quality check algorithms; this approach is investigated here using live GPS and Galileo signals. A modified receiver autonomous integrity monitoring (RAIM) algorithm, including geometry and separability checks, is proposed to detect and exclude erroneous measurements: the multi-constellation approach provides redundant measurements, and RAIM exploits them to exclude distorted observations. The synergy between combined GPS/Galileo navigation and RAIM is analyzed using live data; the performance is compared to the accuracy and availability of a GPS-only solution. The tests performed demonstrate that the methods developed are effective techniques for GNSS-based navigation in signal-degraded environments. The joint use of the multi-constellation approach and of modified RAIM algorithms improves the performance of the navigation system in terms of both accuracy and availability.
在信号退化的环境中，基于全球导航卫星系统（GNSS）的导航是一项具有挑战性的任务，在这种环境中，GNSS信号会因多径效应而失真，并因衰落效应而衰减：导航解决方案可能不准确或无法使用。提高准确性和可用性的一种可能方法是联合使用来自不同GNSS的测量值和质量检查算法；本文使用实时GPS和伽利略信号对这种方法进行了研究。提出了一种改进的接收机自主完好性监测（RAIM）算法，包括几何和可分离性检查，以检测和排除错误测量值：多星座方法提供了冗余测量值，RAIM利用这些测量值排除失真的观测值。使用实时数据对GPS/伽利略组合导航与RAIM之间的协同作用进行了分析；将其性能与仅使用GPS的解决方案的准确性和可用性进行了比较。所进行的测试表明，所开发的方法是在信号退化环境中基于GNSS导航的有效技术。多星座方法和改进的RAIM算法的联合使用在准确性和可用性方面都提高了导航系统的性能。
