Evaluation and definition of a reference maritime multipath model for GNSS receivers

The purpose of this paper is to define a reference maritime multipath model for supporting analysis and simulation in GNSS receivers. A maritime multipath model considering specular and diffuse scattering, depending on sea state as implemented in ESA activity Physical-Statistical Models for Mobile Satellite Communication Systems Below 10 GHz (PhyStat) has been used for the analysis of GNSS receivers performance in maritime environment considering different dynamics, platforms and sea state conditions. A number of realisations of the model were generated varying the range of model parameters. The realisations of the communication channel were adapted into a Spirent GNSS constellation simulator for receiver testing. The assessment considered a sensitivity analysis of the number of echoes versus effects on fading, carrier phase and pseudorange errors. The paper presents a recommendation for model parameters to be used for the implementation in the constellation simulator in order to evaluate the expected GNSS receiver performance for COTS receivers. The work is validated comparing the model implementation applied to a receiver through Spirent simulator, to the measurements collected by a GNSS receiver installed on a medium vessel.