An Accurate High-Order Errors Suppression and Cancellation Method for High-Precision Airborne POS

Synthetic aperture radar imaging requires precise position information provided by position and orientation system (POS), especially sensitive to high-order errors of position information, whereas high-order errors of global positioning system (GPS) are normally ignored in POS solution procedure. For high-precision POS, high-order errors become a significant error source with decisive effects on the accuracy of POS. In this paper, we propose a GPS high-order position errors suppression and cancellation method, which includes the traditional GPS/inertia navigation system (INS) integrated method used as the high-frequency filter, and the low-frequency filter is based on least squares support vector machine. The high- and low-frequency dual filters are constructed to suppress and eliminate high-order error. In verifying our dual-rate hybrid filtering method, POS flight experiments were conducted in November and October up to December in 2015, with results showing that the high-order position accuracy of high-precision POS (0.01°/h gyro drift) is better than 0.006 m, and the proposed method has a better performance compared with other methods.