Adaptive switching method for single-frequency multi-frequency GNSS receiver tracking loop

Abstract

A single-frequency multi-frequency GNSS receiver tracking loop adaptive switching method, the GNSS digital intermediate frequency signal is collected through the radio frequency front end of the hardware platform of the GNSS receiver, and the index reflecting the environmental change is calculated and compared with the preset threshold to select the single-frequency multi-frequency GNSS receiver. Closed-loop tracking with frequency tracking loop or multi-frequency tracking loop. The present invention adjusts the switching state of the loop by selecting indicators that can reflect environmental changes and setting corresponding thresholds for detection. When the signal quality is good, use the independent tracking mode of each frequency point to reduce the amount of calculation and the interference of other frequency point observations. When the signal quality is degraded and the lock is easy to be lost, the multi-frequency joint tracking mode is used to assist the observations of normal signals at other frequency points to improve the robustness and anti-interference ability of the GNSS receiver. Therefore, the tracking method of single-frequency independent and multi-frequency assisted adaptive switching can improve the positioning reliability, accuracy and continuity of GNSS receivers, and has great potential value.

Description

technical field [0001] The invention relates to a technology in the field of satellite navigation, in particular to a single-frequency multi-frequency global satellite navigation system (GNSS) receiver tracking loop adaptive switching method. Background technique [0002] High-reliability satellite navigation receivers have broad application prospects in application scenarios such as unmanned aerial vehicles, Internet of Vehicles, and automatic driving, and have attracted widespread attention at home and abroad. The global satellite navigation system (GNSS) can provide all-weather navigation position information for the above scenarios, enabling drones or vehicles to achieve absolute positioning. However, the quality of GNSS signals is easy to deteriorate, which brings many difficulties to the design of GNSS receivers. Specifically, it is reflected in: 1. The GNSS signal is an open transmission channel from the satellite transmitter to the user receiver. The ionospheric sci...

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Problems solved by technology

[0003] The present invention aims at the problem that the existing single-frequency GNSS receiver has tracking loss of lock in a challenging environment, and the problem that the existing multi-frequency receiver has too much calculation and the mutual influence of observations between different frequency points in a normal environment, and proposes A single-frequency multi-frequency GNSS receiver tracking loop adaptive switching method, selecting indicators that can reflect environmental changes, setting corresponding thresholds for detection, and adjusting the switching state of the loop

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