Nonlinear-filtering-based satellite navigation tracking loop lock loss detection method

Abstract

The invention discloses a nonlinear-filtering-based satellite navigation tracking loop lock loss detection method, which comprises the following steps of: (1) determining the state quantity and observed quantity of a satellite signal tracking loop; (2) establishing a state equation and an observation equation corresponding to the state quantity and the observed quantity obtained by the step (1) respectively; (3) establishing a satellite navigation tracking loop filter based on the state equation and the observation equation obtained by the step (2); (4) setting a false alarm probability according to the counting characteristics of a fault detectable quantity, and determining a detection threshold under the condition of the false alarm probability; (5) setting a loop updating cycle, and calculating a covariance matrix of information in loop updating of each time; (6) setting a lock loss detection cycle to be integrally times the loop updating cycle and not less than the loop updating cycle; (7) calculating the fault detectable quantity in detection of each time, and comparing the fault detectable quantity with the detection threshold; and (8) if the fault detectable quantity is greater than the threshold, resetting the loop filter. By the nonlinear-filtering-based satellite navigation tracking loop lock loss detection method provided by the invention, tracking loop lock loss caused by the sudden change of the observed quantity can be effectively detected, and the filter can be timely reset, thereby improving the fault tolerance and robustness of the nonlinear-filtering-based satellite navigation tracking loop.

Description

technical field [0001] The invention relates to a method for detecting out-of-lock of a tracking loop of a satellite navigation receiver based on nonlinear filtering, and its application scope is mainly the satellite signal tracking loop based on a software receiver. Background technique [0002] In recent years, satellite navigation and positioning systems have been more and more widely used, and have made great progress in high precision, real-time, all-weather and other aspects. General-purpose satellite navigation receivers can already output more accurate position, speed and time information, so as to meet the needs of positioning, navigation and timing under normal circumstances. However, some complex environments and special carrier application scenarios require the receiver to have high sensitivity, high dynamics and high anti-interference performance at the same time, thus putting forward new requirements for the signal processing capability of the receiver, especia...

AI Technical Summary

Problems solved by technology

In the ordinary satellite signal tracking loop, the lock detection is usually done by the lock detector, but this method is not suitable for the nonlinear filter tracking loop

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