摘要
在载体处于高速运动的条件下,导航信号可能随时被遮挡、衰落、干扰,同时载波多普勒的快速变化,导致利用载波相位平滑伪距来提高定位精度的方法不再适用。此外,在以载波多普勒积分值代替载波相位平滑伪距的传统方法中,由于采用固定窗计算平滑伪距初值,极易将奇异值或者误差较大的伪距观测量包含到初值中,而且随着时间增长,载波多普勒的累积误差会越来越大。为解决上述问题,研究了基于滑动窗处理伪距初值的积分多普勒伪距平滑算法。该算法通过滑动精估窗实时计算伪距初值,以此为基础,利用平滑窗内的多普勒加权累积和计算出伪距变化量,实现伪距观测量平滑。在充分考虑了电离层、累积误差等因素的基础上设计了精估窗和平滑窗的长度。静态定位实验和高动态模拟飞行试验结果均表明,该算法可以有效提高接收机的导航定位精度,同时解决了传统方法中异常值影响平滑初值和载波多普勒误差累积问题。
The navigation signals can be blocked,faded and interfered,when a satellite navigation receiver is carried by high dynamic vehicles and working in complex environments.Besides,the carrier Doppler measurements in the navigation receiver will rapidly change due to high dynamics.As a result,the algorithms of smoothing the pseudorange measurements with the carrier-phase measurements are no longer applicable.Furthermore,the conventional techniques of smoothing the pseudo-range measurements with the integral of carrier Doppler measurements,generally use a fixed window for calculating the initial value of pseudoranges,and then can cause a large error in the initial value if the measurements with significant biases or the outliers are involved in the fixed window.In addition,the error in the integral of carrier Doppler measurements is accumulated over the smoothing time.Therefore,an improved algorithm of smoothing the pseudo-range measurements with the integral of carrier Doppler measurements is proposed.By employing a sliding window to replace the fixed window for calculating the initial value of pseudoranges,more accurate initial values for smoothing can be estimated.And the changes in pseudorange are calculated based on the weighted accumulation of carrier Doppler measurements.In consideration of the ionospheric variations,accumulated error and other factors,the lengths of the sliding window and the consequent smoothing window are chosen.The experimental results in both the static positioning and the simulated flight navigation show that the positioning accuracy is improved.Moreover,the estimation error in the initial value of pseudoranges and the accumulated error in the integral of carrier Doppler measurements are efficiently reduced.
作者
殷彪
耿生群
赵昀
Yin Biao;Geng Shengqun;Zhao Yun(School of Electronics and Information Engineering,University of Aeronautics and Astronautics,Beijing 100191,China)
出处
《电子技术应用》
2018年第12期81-84,共4页
Application of Electronic Technique
关键词
高动态
滑动窗
平滑初值
积分多普勒
伪距平滑
high dynamic
sliding-window
smoothing initial value
integral Doppler
smoothing pseudorange
