Mitigating multipath errors using semi-parametric models for high precision static positioning

Abstract

Carrier phase multipath is currently the main error source for high precision and short distance Global Positioning System (GPS) applications, such as deformation monitoring of open pit walls and dame. Although important progress has been made to mitigate the impact of multipath errors on positioning results, more practicable methods need to be developed. In this paper, the semi-parametric model and penalised least squares method have been developed for mitigation of multipath errors. In the semi-parametric model, multipath is described by a complicated, but smoothly varying, function with time. The functions, parameters, such as the coordinates of sites and ambiguities, and observation noise are decomposed using the penalised least squares method. The potential of the semi-parametric model to reduce multipath to the level of receiver noise is demonstrated on a static GPS baseline. The improvement of the precision and reliability of ambiguity resolution and positioning results using the semi-parametric model over the parametric model,(standard GPS data processing techniques) is also discussed.