Abstract:

The possibility of multiple outliers should not be neglected in measurements for the increment number of the navigation satellites, and the RAIM based on the single-outlier hypothesis can not provide effective restraining against multiple outliers . The robust estimation is focused widely. A robust positioning algorithm is presented for resisting multiple outliers which make the traditional M-estimator ineffective. The robustness can be improved by the modified positioning algorithm. To handle the biased convergence problem, the robust estimate of the initial values is realized by modifying the S-estimation with available satellite number in real time. Positioning results of the actual GPS measurements show that the proposed method resists multiple outliers effectively.

Key words: Global Navigation Satellite System (GNSS), Positioning, Robust estimation, Fault detection, M-estimation, S-estimation