Characterization of GNSS Multipath in Nominal Open-Sky Scenario for Safe Railway Localization

Kurzfassung

Railway transportation systems have high accuracy and high integrity demands for safe localisation. There has been an increased interest in using GNSS (Global Navigation Satellite Systems), but its position determination in urban environment can be highly degraded because of the presence of reflected signals (i.e. multipath). This paper tackles the characterisation of multipath in code measurements caused exclusively by the vehicle and the antenna installation. First, Code-Minus-Carrier (CMC) method for autonomously isolating multipath is presented. Second, an error model of the isolated multipath based on Gaussian overbounding is derived. The presented methodology is supported by real measurements collected in an open-sky Railway scenario with a commercial and an experimental train.