Chapter 4 - GNSS multipath errors and mitigation techniques

Global Navigation Satellite System (GNSS) is widely used for navigation and positioning in engineering and geoscience applications. Depending on the measurement types (pseudorange and carrier-phase measurements) and error/bias models used in data processing, GNSS can achieve meter to centimeter level or better positioning accuracy. Multipath is not modeled in GNSS data processing usually; it can lead to errors of few meters in pseudorange measurements and few centimeters in carrier-phase measurements. Therefore, multipath errors may limit the standard positioning service to few meters and high-precision positioning to few centimeters. This chapter describes the multipath error source, the characteristics in measurements, and the factors affecting the magnitude of multipath errors. Moreover, the state-of-the-art multipath mitigation methods are described and discussed. This chapter contains all you need to understand GNSS multipath errors and their characteristics and state-of-the-art hardware- and software-based multipath mitigation techniques.