Multiple Reference Consistency Check Method for BDS Sea-Based JPALS

Abstract

Landing manned and unmanned aerial vehicles autonomously on an aircraft carrier using Global Navigation Satellite System (GNSS) is an important capability to research and develop. The United States Navy has developed a navigation system called Sea-Based Joint Precision Approach and Landing System (JPALS) to deliver this capability. Because of the severe constraints on runway length and the significant consequences of failed landings at sea, guidance quality requirements are significantly strict for sea-based operation. Thus the Sea-Based JPALS requires high accuracy and integrity performance. Multiple Reference Consistency Check (MRCC) is an important carrierborne integrity monitor. There is also MRCC monitor for Ground Based Augmentation System (GBAS), but due to the dynamic of the ship and the different positioning method, Sea-based JPALS MRCC is different from that for GBAS. Besides, previous studies for Sea-based JPALS MRCC are mostly based on GPS, not considering BDS, and the thresholds are not applicable to BDS. Therefore, this paper focuses on the BDS-based MRCC for Sea-Based JPALS. We describe a detailed implementation method for MRCC, and propose a construction method for B-value. Then we use BDS and GPS real data to calculate B-values based on the described method, compare the B-value characteristics of GPS, BDS GEO, BDS IGSO and BDS MEO satellites, and develop an exponential fitting threshold model for B-values of each measurement. Finally, the simulated step fault and ramp fault are injected into original measurements to test the fault detection and exclusion performance of MRCC, and analyze the impact of the MRCC monitor on the relative positioning accuracy. Results show that MRCC helps prevent large positioning errors caused by reference receiver faults and maintain the positioning accuracy of Sea-Based JPALS.