Benefit Analysis of GALILEO to Improve Reliability of GNSS Localization in Harsh Environments

Pierre Reisdorf, Andreas Auerswald, Gerd Wanielik, Marcus Obst

Abstract:	Reliable and accurate positioning for road transport applications is still an active field of research. Especially in the light of the upcoming automated driving, cost-efficient Figure 1: Simulation of expected theoretical HDOP for a multi-constellation scenario with GPS and Galileo (subset from 2014) satellites. The simulation program was GSSF [11]. and reliable positioning systems are a crucial prerequisite. The requirements in terms of characteristics such as availability, accuracy and integrity are steadily increasing for different obstructed scenarios such as urban environments. In general, the aim of any localization approach is to determine a precise and reliable vehicle position based on sensor information acquired from satellite observations. These observations are typically subject to significant uncertainties. Satellite navigation is an appealing technology to solve this task as it provides a straightforward solution for the absolute positioning task with decent performance under good environmental conditions. Nevertheless, there are situations such as in urban canyons where the classical satellite navigation approaches either fail or deliver inconsistent results. Especially the handling of non-line-of-sight (NLOS) measurements—which is also often described by the generic term multipath—is a challenging task. If such suspicious observations are not handled carefully an underestimated position error can lead to severe traffic accidents. Hence, knowing about a low accuracy is better than pretending a high accuracy. With the availability of the upcoming GNSS Galileo the performance of the approaches in [1] will certainly increase. In Figure 1 a simulation of the expected theoretical Horizontal Dilution of Precision (HDOP) for a multi-constellation scenario with GPS and Galileo is shown. This simulation indicates a decreasing of the theoretical HDOP for this scenario. It can be concluded that any positioning system targeting safety applications has to exploit as much information as possible. On the same time, it is important to constantly assess the quality of the measurements and prevent distorted observations from negatively influencing the positioning result. Thus, there is a clear advantage in increasing the number of satellites with an additional satellite system in orbit in order to enable robust and reliable positioning.
Published in:	Proceedings of the 27th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2014) September 8 - 12, 2014 Tampa Convention Center Tampa, Florida
Pages:	940 - 946
Cite this article:	Reisdorf, Pierre, Auerswald, Andreas, Wanielik, Gerd, Obst, Marcus, "Benefit Analysis of GALILEO to Improve Reliability of GNSS Localization in Harsh Environments," Proceedings of the 27th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2014), Tampa, Florida, September 2014, pp. 940-946.
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