Method for inertial information assisting GNSS tracking loop

Abstract

The invention discloses a method for inertial information assisting a GNSS tracking loop. The method includes the steps that according to the carrier position, speed and accelerated speed information provided by an inertial navigation system, combined with the information such as local time and a satellite ephemeris, Doppler shifts and Doppler shift change rates of all channel satellites of a GNSS receiver are calculated in real time, the difference information of a tracking loop carrier frequency shift measurement value and a corresponding Doppler shift calculation value is taken as an observation quantity, frequency deviation caused by mechanical vibration of a carrier and crystal oscillator frequency drift of the receiver is calculated by the adoption of an alpha-beta filtering method, a carrier frequency shift predicted value is obtained to correct the tracking loop in a feedforward mode, and the step of inertial information assisting the GNSS tracking loop is finished. The dynamic stress action on the tracking loop by high dynamic is reduced, frequency deviation caused by mechanical vibration of the carrier and crystal oscillator frequency drift of the receiver is eliminated, dynamic adaptability and navigation stability of the GNSS receiver are improved, and the application prospects are wide.

Description

technical field [0001] The invention relates to the field of satellite navigation and integrated navigation, in particular to an inertial information assisted GNSS (global navigation satellite system) tracking loop method. Background technique [0002] During the flight of precision-guided weapons such as missiles and rockets, the transmission of satellite signals from the satellite to the carrier will cause a large frequency offset and change rate of the carrier. The main influencing factors are the relative motion between the satellite and the carrier, the carrier mechanical Vibration, receiver crystal oscillator frequency drift and satellite clock frequency drift, etc., it is difficult to achieve stable tracking of satellite signals by using a conventional tracking loop in a highly dynamic environment, and the signal may lose lock or even lose navigation capabilities. [0003] At present, in order to meet the continuous improvement of navigation performance requirements o...

AI Technical Summary

Problems solved by technology

[0002] During the flight of precision-guided weapons such as missiles and rockets, the transmission of satellite signals from the satellite to the carrier will cause a large frequency offset and change rate of the carrier. The main influencing factors are the relative motion between the satellite and the carrier, the carrier mechanical Vibration, receiver crystal oscillator frequency drift and satellite clock frequency drift, etc., it is difficult to achieve stable tracking of satellite signals by using a conventional tracking loop in a high dynamic environment, and the signal may lose lock or even lose navigation capabilities

[0003] At present, in order to meet the continuous improvement of navigation performance requirements of modern precision-guided weapons, inertial information such as carrier position, velocity, and acceleration provided by the inertial navigation system is used to improve the navigation performance of the receiver, combined with information such as local time and satellite ephemeris, real-time calculation The Doppler frequency shift and its rate of change of satellite signals in each channel of the GNSS receiver, but even with the assistance of precise inertial information in the actual tracking loop, due to factors such as carrier mechanical vibration and receiver crystal oscillator frequency drift, there is still a certain frequency Offset, cannot completely eliminate the dynamic stress effect of high dynamics on the tracking loop and the frequency offset caused by carrier mechanical vibration, clock drift, etc., so the dynamic adaptability and navigation stability of the GNSS receiver are poor

Images