| In spite of the fact that many multipath mitigation techniques are currently implemented in GPS hardware and firmware, there remains a post-receiver-processed multipath error which plagues GPS observations stored in the RINEX files. At static Continuously Operating Receiver Station (CORS) sites, this multipath error expresses sidereal periodicity by virtue of the repeated configuration of the GPS satellite relative to the ground-borne GPS antenna and its environment.;In this study, this repeatability was capitalized upon to investigate the multipath signal (its variability inclusive) generated at a highly multipath-prone Suominet CORS site (named SG03). In this regard, the multipath was parameterized using a Fourier Analysis and a Wavelet Analysis technique. The latter was found to capture in excess of 90% of the identified signal, outperforming the Fourier parameterization.;Therefore, investigation of an optimal multipath modeling technique (in this case using a third order one-dimensional Daubechies wavelet) served as a pre-cursor to the main focus of this study, that being to construct an Integrated Point Position and Multipath Prediction (IPPMP) algorithm at a static CORS site. To this end, five different IPPMP algorithms were developed in MATLAB based on three types of prior-information models, namely, the Extended Gauss-Markov Model, the Mixed Linear Model and the Random Effects Model. While it is true that other wavelet-based mitigation schemes (such as the trademarked Wavesmooth(TM) technique) exist, the implementation of this study emphasized both the mitigation as well as the inclusion of multipath parameters in the IPPMP schemes developed.;The results of this study suggest that use of an elevation-dependent variance model for the high frequency wavelet parameters (called wavelet details) is insignificant to the position determination. It was confirmed that the use of the Random Effects Model is useful where the prior information is actually bias-prone, this model being more suitable to high precision positioning applications. Inclusion of the multipath parameters in the IPPMP models did indeed improve the position determination capability, but only where the receiver coordinates were sequentially-updated---the influence of the prior coordinate values on the solution was greater than that of the multipath prior information. The solution convergence rate was understandably-higher the more accurate the initial coordinates.;Ultimately, the results of this study suggest that there is value in parameterizing the multipath signal at stationary CORS sites with the intention of minimizing the impact of the multipath on position determination at static locations. |
