TY - JOUR AU - Xuefen Zhu AU - Fei Shen AU - Jianfeng Chen AU - Yang Yang AU - Dongrui Yang AU - Xiyuan Chen PY - 2015/09/11 Y2 - 2024/03/29 TI - Combined Tracking Strategy Based on Unscented Kalman Filter for Global Positioning System L2C CM/CL Signal JF - Defence Science Journal JA - DSJ VL - 65 IS - 5 SE - Engineering Science & Technology DO - 10.14429/dsj.65.8725 UR - https://publications.drdo.gov.in/ojs/index.php/dsj/article/view/8725 AB - 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. ER -