Combined incoherent integral vector tracking method based on spatial domain

Abstract

The invention discloses a combined incoherent integral vector tracking method based on a spatial domain, so as to further improve the performance of a vector tracking GPS receiver. In a new vector tracking strategy design, a phase discriminator / frequency discriminator in the traditional vector tracking loop is abandoned, baseband signals of visible satellites of all channels serve as observed quantities after being subjected to incoherent integration, and position, speed, clock bias and the like of the GPS receiver are directly solved by using an EKF for estimating the observed quantities. Due to the existence of incoherent integral operation, the carrier-to-noise ratio of the observed quantities can be effectively increased and the tracking sensitivity can be increased when the GPS satellite signal is weak.

Description

technical field [0001] The present invention is applicable to the navigation and positioning technical fields with medium and low precision requirements such as urban traffic, navigation, etc., in order to meet the navigation and positioning requirements of high precision, high reliability and large positioning coverage, and research new technologies on the basis of traditional GPS software receiver technology. Advanced satellite signal tracking technology realizes seamless positioning in environments with weak satellite signals and high dynamics. Background technique [0002] In a highly dynamic environment (aerospace, launch vehicles, satellites and missiles), the GPS receiver is in a state of high-speed motion, and may have a large acceleration or jerk, and general commercial GPS receivers cannot work normally. In a highly dynamic environment, the high receiver motion speed causes a large Doppler shift on the carrier. In addition, when the receiver changes motion state wi...

AI Technical Summary

Problems solved by technology

[0003] (1) It is necessary to complete the acquisition process as soon as possible and enter the tracking process. Too large Doppler frequency shift will bring great difficulties to the initial tracking. At this time, the tracking loop can only use a wide bandwidth frequency-locked loop or PLL

[0004] (2) Since the Doppler frequency shift changes drastically, the integration time must be very short, otherwise it is easy to exceed the tracking bandwidth of the phase-locked loop or frequency-locked switch, resulting in signal loss of lock

[0005] (3) When tracking the signal in a high dynamic environment, because the carrier Doppler frequency changes drastically, a shorter integration time and a larger filter noise bandwidth are used, so the loop signal-to-noise ratio is usually low , poor tracking accuracy

[0007] However, the traditional vector tracking technology does not make full use of the inherent relationship of each channel signal, and it cannot be called a true vector tracking technology.

Images