GPS weak signal tracking method in high dynamic environment

Abstract

The invention provides a GPS weak signal tracking method in a high dynamic environment. Problems that lock losing is likely to happen due to a narrow single phase locked loop noise bandwidth and too much noise is likely to be introduced due to a wide single frequency locked loop noise bandwidth when the GPS is in the high dynamic environment are solved in a new mode of using a two-order frequency locked loop (FLL) to assist a three-order phase locked loop (PLL) formed by the phase locked loop and the frequency locked loop. A UKF filter mode is combined to track weak signals. A nonlinear Kalman filler mode is adopted to enable a receiver to process signals with a low carrier to noise ratio. Signals tracked by the front phase locked loop and the frequency locked loop pass through the UKF filter, the UKF filter estimates a position, a speed, clock skew and a clock frequency difference, and thus a code phase and a carrier frequency are corrected. In the GPS high dynamic and multipath complex environment, a new research method is provided, and a strong promotion ability is provided.

Description

technical field [0001] The invention relates to the technical field of signal tracking, in particular to a GPS weak signal tracking method in a high dynamic environment, and is especially suitable for GPS high dynamic and multi-path conditions in a complex environment. Background technique [0002] In recent years, GPS has gradually been widely used in military and civilian fields due to its all-weather, high precision, continuity, and low cost advantages. GPS generally receives satellite signals through receivers. The general positioning process includes signal acquisition, signal tracking and Navigation calculation, so when the satellite signal is captured, the GPS signal must be tracked, and the tracking effect directly determines the accuracy of the GPS positioning. [0003] Ordinary GPS receivers use independent tracking channels to track different satellites, because it is easy to lose lock in a high dynamic environment with a separate phase-locked loop. In addition, G...

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Problems solved by technology

[0003] Ordinary GPS receivers use independent tracking channels to track different satellites, because it is easy to lose lock in a high dynamic environment with a separate phase-locked loop. In addition, GPS positioning mainly relies on satellites for positioning, but in some environments , due to the occlusion of buildings, trees, etc., it is difficult for GPS to capture these weak signals. In addition, GPS may be in a high dynamic environment. Therefore, in order to improve the positioning accuracy of GPS in the face of these complex environments, carrier frequency auxiliary Phase combined with UKF algorithm to enhance the tracking of GPS receivers for high dynamic weak signals

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