Tracking method and tracking system for high dynamic GNSS carrier wave signals

Abstract

The invention discloses a tracking method and a tracking system for high dynamic GNSS carrier wave signals. The tracking method comprises steps of initial demodulation and pre-detection integration; estimation on a Doppler frequency of a present carrier wave signal and an acceleration speed in a satellite direction; secondary demodulation; carrier wave phase detection and navigation text extraction; loop update and re-demodulation. The tracking system comprises a first carrier wave voltage control oscillator, a pre-detection integrator, a fractional order Fourier converter, an acceleration speed estimator, a high dynamic frequency monitor, a second carrier wave voltage control oscillator, a phase monitor and a tracking filter. According to the tracking method and the tracking system, the extremely high dynamic carrier wave signals can be tracked by a receiver, restriction of a loop bandwidth on dynamic tracking capability is released, influence of dynamic levels on detection is reduced, tracking loop design is simplified, and a use scope of a GNSS receiver based on Beidou / GPS is expanded.

Description

technical field [0001] The invention relates to the technical field of satellite navigation, in particular to a tracking method and system for a high dynamic GNSS carrier signal. Background technique [0002] GNSS stands for Global Navigation Satellite System, GlobalNavigationSatelliteSystem. A satellite navigation receiver acquires and tracks the signals of multiple GNSS satellites and then demodulates the navigation data modulated therein. The satellite navigation receiver uses the ranging code to calculate the relative distance between the GNSS satellite and the user, uses the ephemeris data in the navigation data to solve the satellite position and time model, and then calculates the user's position. [0003] Navigation using GNSS signals (such as GPS, Beidou, GLONASS, etc.) has been widely used in space low-orbit satellites, missiles, and ground targets. When the carrier is running in an environment with high speed, high acceleration and high jerk, the Doppler effect ...

AI Technical Summary

Problems solved by technology

[0006] (1) Loop bandwidth limitation: In the traditional tracking method, there is a contradiction between loop bandwidth and tracking accuracy: the higher the bandwidth, the greater the dynamic range of carrier tracking, but at the same time, the energy of the high dynamic carrier will also be distributed to its bandwidth range Within, the tracking accuracy is significantly reduced, so in order to ensure the tracking accuracy, the dynamic range that the loop can tolerate has to be limited;

[0007] (2) It is difficult to accurately detect the dynamic level: whether it relies on the frequency estimation in the loop or the IMU in the strapdown inertial navigation system, there is a problem that the acceleration and jerk of the carrier cannot be measured accurately and in real time. It affects the tracking of the receiver to the GNSS signal;

[0008] (3), the design of the tracking loop is complex: the existing high dynamic tracking method, or the order of the tracking loop is high, the amount of calculation is large, or it is greatly affected by the error of the IMU, and error compensation needs to be performed at any time, so the loop's very complex design

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