Traditional and Alternative Network Adjustment Approach for the TAMDEF GPS in Antarctica

Abstract

A network adjustment analysis was derived for a GPS network called TAMDEF (Trans Antarctic Mountains Deformation), located in Victoria Land, Antarctica. The network adjustment strategy involved the careful selection and application of the appropriate approach to process the TAMDEF network. Therefore, for the first part of the presented study, four cases denoted as Cases I–IV were investigated for the TAMDEF network processing with respect to the IGS (International GNSS Service) sites inside and outside the Antarctic continent. Here, the GPS data processing relied on the PAGES (Program for Adjustment of GPS Ephemerides) software, which was set up to run using the Least-Squares adjustment with Stochastic Constraints (SCLESS). The second part of the study focus in considering alternative network adjustment approaches: the Minimum-Norm LESS adjustment (MINOLESS); the Partial Minimum-Norm LESS (Partial-MINOLESS) and the Best LInear Minimum Partial-Bias Estimation (BLIMPBE) to validate results from the SCLESS approach (Case I) for IGS sites inside the Antarctica. Based on the applied network adjustment approaches within the Antarctic tectonic plate, it can be demonstrated that the GPS data used is clean of bias after properly taken care of ionosphere, troposphere and some other sources that affect GPS positioning.