The GPS vector tracking loop based on the iterated unscented unscented Kalman filter under the large initial error

2009 ◽  
Author(s):  
Kwang-Hoon Kim ◽  
Jong-Hwa Song ◽  
Gyu-In Jee
Keyword(s):  
Kalman Filter ◽  
Unscented Kalman Filter ◽  
Initial Error ◽  
Tracking Loop ◽  
Vector Tracking

Study on Vector Tracking Loop Based on Extended Kalman Filter

2014 ◽  
Vol 35 (6) ◽  
pp. 1400-1405 ◽  
Author(s):  
Yu Luo ◽  
Yong-qing Wang ◽  
Hai-kun Luo ◽  
Yuan-xing Ma ◽  
Si-liang Wu
Keyword(s):  
Kalman Filter ◽  
Extended Kalman Filter ◽  
Tracking Loop ◽  
Vector Tracking

scholarly journals Vector Tracking Algorithm Based on Adaptive Cubature Kalman Filter

2018 ◽  
Vol 36 (6) ◽  
pp. 1108-1115
Author(s):  
Xiaojun Zou ◽  
Baowang Lian ◽  
Zesheng Dan
Keyword(s):  
Kalman Filter ◽  
Carrier Frequency ◽  
Phase Error ◽  
Tracking Algorithm ◽  
Frequency Error ◽  
Test Results ◽  
Tracking Loop ◽  
Cubature Kalman Filter ◽  
Vector Tracking ◽  
Present Algorithm

In the vector tracking loop, there is a great error in the output of discriminator owing to the disturbance of noise. Cubature Kalman filter is proposed to replace the discriminator to process I/Q data and generate code phase error and the carrier frequency error in this paper. The present algorithm not only can avoid the nonlinear problem of discriminator, but also can reduce the bad effect of noise. Moreover, using cubature Kalman filter to deal with the nonlinear I/Q data is beneficial to preserve the accuracy of data processing. Because noise is unknown or time-varying, the filter should have the ability to respond to the changes of environmental noise. The innovation of measurements is used to estimate the covariance matrix of measurement noise in real time. Finally, a comparison is carried out between the present algorithm and the vector tracking algorithm based on discriminator. The test results show that the code phase error and the carrier frequency error are smaller, and the accuracy of navigation solution is also higher.

Combined Tracking Strategy Based on Unscented Kalman Filter for Global Positioning System L2C CM/CL Signal

2015 ◽  
Vol 65 (5) ◽  
pp. 395 ◽  
Author(s):  
Xuefen Zhu ◽  
Fei Shen ◽  
Jianfeng Chen ◽  
Yang Yang ◽  
Dongrui Yang ◽  
...  
Keyword(s):  
Kalman Filter ◽  
Global Positioning System ◽  
Unscented Kalman Filter ◽  
Dominant Role ◽  
Tracking Error ◽  
Doppler Frequency ◽  
Positioning System ◽  
Tracking Loop ◽  
Signal Tracking ◽  
Global Positioning

<p>In a global positioning system receiver, the tracking algorithm plays a dominant role since the code delay and Doppler frequency shift need to be accurately estimated as well as their variation over time need to be continuously updated. Combine unscented Kalman filter (UKF) with CM/CL signal to improve the signal tracking precision is proposed. It allow weighting assignment between CM code and CL code incoming signal, masked by a mass of noise, and to describe a UKF tracking loop aiming at decreasing numerical errors. UKF here involves state and measuring equations which calculate absolute offsets to adjust initial code and carrier phase then dramatically decrease the tracking error. In particular, the algorithm is implemented in both open space and jammed environment to highlight the advantages of tracking approach, by comparing single code and combined code, UKF and EKF tracking loop. It proves that signal tracking based on UKF, with low energy dissipation as well as high precision, is particularly appealing for a software receiver implementation.</p>

scholarly journals Design and Validation of a Cascading Vector Tracking Loop in High Dynamic Environments

2021 ◽  
Vol 13 (10) ◽  
pp. 2000
Author(s):  
Zhiyong Tu ◽  
Yidong Lou ◽  
Wenfei Guo ◽  
Weiwei Song ◽  
Yusheng Wang
Keyword(s):  
Unscented Kalman Filter ◽  
Negative Impact ◽  
Dynamic Performance ◽  
Phase Error ◽  
Tracking Error ◽  
Doppler Frequency ◽  
Convergence Time ◽  
Tracking Loop ◽  
Vector Tracking ◽  
High Dynamic

This paper designs a cascading vector tracking loop based on the Unscented Kalman Filter (UKF) for high dynamic environment. Constant improvement in dynamic performance is an enormous challenge to the traditional receiver. Due to the doppler effect, the satellite signals received by these vehicles contain fast changing doppler frequency shifts and the first and second derivatives of doppler frequency, which will directly cause a negative impact on the receiver’s stable tracking of the signals. In order to guarantee the dynamic performance and the tracking accuracy, this paper designs a vector carrier structure to estimate the doppler component of a signal. Firstly, after the coherence integral, the IQ values are reorganized into new observations. Secondly, the phase error and frequency of the carrier are estimated through the pre-filter. Then, the pseudorange and carrier frequency are used as the observations of the main filter to estimate the motion state of the aircraft. Finally, the current state is fed back to the carrier Numerical Controlled Oscillator (NCO) as a complete closed loop. In the whole structure, the cascading vector loop replaces the original carrier tracking loop, and the stable signal tracking of code loop is guaranteed by carrier assisted pseudo-code method. In this paper, with the high dynamic signals generated by the GNSS signal simulator, this designed algorithm is validated by a software receiver. The results show that this loop has a wider dynamic tracking range and lower tracking error than the second-order frequency locked loop assisted third-order phase locked loop in high dynamic circumstances. When the acceleration of carrier is 100 g, the convergence time of vector structure is about 100 ms, and the carrier phase error is lower than 0.6 mm.

Sign in / Sign up

Export Citation Format

Share Document