A Virtual Receiver Concept for Continuous GNSS based Navigation of Inland Vessels

Efficient and economic guidance of inland vessels relies on a continuous, available, reliable and precise GNSS navigation solution. Hence, below other side effects, this is especially critical when passing beneath bridges or similar infrastructures that cross waterways. They have two effects: distortion (reflection, diffraction and interruption) of the incoming GNSS signal by the individual bridge structure on the one hand and along with that, the affected ambiguity resolution for carrier phase observation on the other hand. Thus, disturbances, discontinuities and jumps in the position estimates are present - an extreme critical situation especially for safety-relevant applications. A multi-antenna system for marine applications combined with the concept of a virtual receiver will be presented. This approach strengthen the overall geometry of visible GNSS satellites immediately, and provides continuous position estimates even for challenging passages. Furthermore, a bridging of observations between two or more antennas on a known rigid platform reduces signal interruptions and provides continuous navigation solution under challenging or even critical environmental conditions. Laboratory experiments, driven on a 2,5 hour turn from Hannover on the Mittelland Canal on the inland vessel MS Jenny (MS Science) prove, that various DOP values as well as noise of the position solution are reduced significantly. The observation noise is reduced by up to 0.3-0.4m whereby the position solution for a code based navigation reaches up to 94.5% w.r.t. classical single point positioning. The overall positioning performance is improved by up to 80%