Method for realizing single-mode RAIM (Receiver Autonomous Integrity Monitoring) under small number of visible satellites based on assistance of clock correction

Abstract

The invention discloses a method for realizing single-mode RAIM (Receiver Autonomous Integrity Monitoring) under a small number of visible satellites based on assistance of clock correction, which is a method for realizing single-mode RAIM under the condition that the number of the visible satellites is small in loop tracking. Clock correction prediction is carried out through a Newton interpolation model under the premise that the clock frequency of a receiver is stable, and detection and elimination of a fault satellite can be carried out under the condition that the number of the visible satellites is five, thereby improving the positioning precision, the continuity and the stability of the receiver. The method comprises the steps of: first, determining weight factor in weighted least squares through parameters such as a carrier-to-noise ratio and the like of satellite signals; then, carrying out RAIM availability detection through a false alarm rate, a missed alarm rate, an observation equation and a weight matrix, determining a detection threshold value by using a tolerant false alarm rate in a non-precision condition, and carrying out clock correction prediction for the receiver through the Newton interpolation model so as to realize detection and elimination of the fault satellite, and finally, carrying out analysis and comparison on a dilution of precision (DOP) after a clock correction auxiliary equation is added. The method disclosed by the invention can realize detection and elimination of the fault satellite under the condition that only one redundant satellite exists, reduces the space dilution of precision through the clock correction auxiliary model, and improving the positioning accuracy of the receiver and the system robustness.

Description

Technical field [0001] The invention belongs to the field of satellite navigation, and specifically is a method for monitoring the autonomous integrity of a low-visibility sub-satellite receiver based on a Newton interpolation clock difference model prediction. Background technique [0002] The Global Navigation Satellite System (GNSS) plays an extremely important position in both military and civil fields. GNSS can provide positioning, navigation and timing for objects at all levels of sea, land, and air, including ocean navigation and advancement of ships. Port water diversion, autonomous vehicle navigation, aircraft route guidance, approach and landing, power, post and telecommunications network systems, and school frequency. Receiver Autonomous Integrity Monitoring (RAIM) ensures the accuracy, continuity and robustness of user positioning and timing results, and provides a guarantee for the normal operation of the GNSS system. [0003] In some scenarios, such as building occlu...

AI Technical Summary

Problems solved by technology

In practical applications, the weighted least squares method is mainly used for fault detection and elimination of a single satellite. In the traditional mode, five satellites can be used for fault detection and six satellites can be used for troubleshooting. However, when buildings are blocked, urban canyons or Indoors, sometimes the situation of six visible satellites cannot be satisfied. Therefore, it is necessary to explore a new method so that the receiver can detect and eliminate faulty satellites when there is only one redundant satellite (that is, five visible satellites). , so as to realize the autonomous integrity monitoring of the receiver

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