基于自适应强跟踪Kalman滤波的GNSS跟踪环路设计  

Design of a Tracking Loop Using Adaptive Strong Tracking Kalman Filter in GNSS Receivers

作　　者：盛开宇 陈熙源[1,2] 汤新华[1,2] 闫晣 高宁 SHENG Kaiyu;CHEN Xiyuan;TANG Xinhua;YAN Zhe;GAO Ning(School of Instrument Science and Engineering,Southeast University,Nanjing Jiangsu 210096,China;MOE Key Laboratory of Micro-Inertial Instrument and Advanced Navigation Technology,Nanjing Jiangsu 210096,China)

机构地区：[1]东南大学仪器科学与工程学院,江苏南京210096 [2]微惯性仪表与先进导航技术教育部重点实验室,江苏南京210096

出　　处：《传感技术学报》2024年第1期35-41,共7页Chinese Journal of Sensors and Actuators

基　　金：国家自然科学基金项目(61873064);江苏现代农业产业关键技术创新项目(CX(21)2015);苏州市科技计划项目合同(SNG2020039)。

摘　　要：为提高GNSS接收机跟踪环路在复杂环境下的跟踪性能,提出一种基于自适应强跟踪Kalman滤波(ASTKF)的跟踪环路,在传统跟踪环路的基础上,以鉴相器输出为观测量进行自适应强跟踪Kalman滤波,滤波结果用于计算导航滤波器的观测量,同时将伪码频率和载波多普勒频率反馈到码NCO和载波NCO,在ASTKF中使用基于卡方分布的渐消因子计算方法,提升跟踪环路鲁棒性。半物理仿真实验表明,相比于基于Kalman滤波的跟踪环路和基于强跟踪Kalman滤波(STKF)的跟踪环路,所提出方法在水平方向上的位置误差和速度误差减小20%以上,有效提高了卫星导航接收机的定位性能。In the tracking stage of a GNSS receiver,in order to enhance the tracking performance of the loop in harsh environments,a tracking loop based on adaptive strong tracking Kalman filter(ASTKF)is proposed.A system model taking account of carrier phase,code phase,carrier frequency,etc.is developed,and the phase discriminator outputs are used as the measurements to update ASTKF.The main estimates including carrier frequency and phase are fed back to both code NCO(Numerically Controlled Oscillator)and carrier NCO,and the calculation method of the fading factors based on the chi square distribution is used in ASTKF,so the robustness of the tracking loop can be improved.The semi physical simulation results show that the proposed method reduces the position error and veloc-ity error by more than 20%in contrast to the tracking loop based on Kalman filter or strong tracking Kalman filter(STKF),effectively improving the tracking and positioning performance of GNSS receiver.

关 键 词：卫星导航 自适应强跟踪Kalman滤波 渐消因子 卡方分布 软件接收机 

分 类 号：U666[交通运输工程—船舶及航道工程]