Multipath mitigation based on trend surface analysis applied to dual-antenna receiver with common clock

Multipath mitigation methods based on the intrinsic spatiotemporal repeatability of multipath effect are commonly applied in high-precision Global Navigation Satellite System positioning. Among which multipath hemispherical map (MHM) has the advantages of simplicity of calculation and real-time multipath reduction of static environment or some dynamic environment. However, utilizing the average of residuals as the calibration values will inevitably lead to insufficient or excessive modification of multipath in the lattice. We proposed an advanced multipath elimination method named trend surface analysis-based multipath hemispherical map (T-MHM), which extends the primary MHM by combining the trend surface analysis method to investigate the multipath spatial distribution and trend in each lattice. A short baseline experiment was carried out using a dual-antenna receiver with common clock in campus of East China Normal University. Single-difference carrier residuals were used for relative multipath modeling. The multipath elimination results indicate that, compared with the original approach, the T-MHM improves the dispersion and accuracy of the baseline solution and increases the phase observation residuals reduction rate. It also enhances the modeling of multipath information in both low- and high-frequency bands. Meanwhile, T-MHM is less sensitive to lattice size. In practical applications, larger lattice size can be adopted to improve the computational efficiency and spatial coverage with little loss of accuracy.