Space station GPS multipath analysis and validation

Significant progress has been made in the Global Positioning System (GPS) receiver technology. Unfortunately, multipath remains as an unsolved problem for high precision applications. In order to design a GPS receiver that is capable of multipath suppression or compensation, a full understanding of the nature of the multipath is necessary. A comprehensive multipath simulation tool is thus important for GPS receiver developers that intend to incorporate effective multipath mitigation techniques. A GPS multipath simulation tool based on the electromagnetic modeling technique-the uniform geometrical theory of diffraction (UTD) is proposed for the International Space Station (ISS) Program. It is demonstrated that the GPS carrier phase errors due to multipath can be simulated and predicted using the electromagnetic modeling technique such as the UTD.