摘要
一般卫星导航接收机的伪距测量误差大于宽巷波长。根据宽巷引导模型,直接使用双差伪距取整固定双差宽巷整周模糊度有很大概率会产生一周固定错误。基于此,提出了一种改进的宽巷引导整周模糊度固定算法,针对宽巷整周模糊度一周固定错误进行探测和修复。利用整周模糊度为整数的特质构造理论探测量,并将该探测量与载噪比所确定的门限相比较,判断是否出现宽巷整周模糊度一周固定错误;利用双差整周模糊度自由度为3的特点,修复错误宽巷整周模糊度。对该算法在高斯噪声条件下的可行性进行了理论分析,结果表明正常载噪比的观测数据均可分辨出一周宽巷整周模糊度的估计错误。同时,分析了考虑多径等误差后该算法所能接受的载波相位最大误差。计算了不同伪距误差下宽巷整周模糊度一周固定错误出现的概率。使用GPS实测短基线数据对算法进行验证,该算法可将基于宽巷引导的整周模糊度固定算法的固定率从原来的只有不到1/3提升至接近100%。
In most GPS（Global Positioning System）receivers,the pseudo-range measurement error is bigger than the wavelength of WL（Wide Lane）carrier phase measurement.It will probably cause one cycle WL integer ambiguity resolution error in case the DD（Double Differenced）WL integer ambiguity is rounded by DD pseudo-range measurement according to the WL integer bootstrapping model.In this view of,we propose a modified WL bootstrapping ambiguity resolution algorithm.The proposed algorithm mainly aims at detecting and repairing one cycle WL integer ambiguity error.The WL integer ambiguity error detector is designed according to the characteristic that the integer ambiguity is an integer.The designed detector is compared with the theoretical threshold calculated by the Carrier Noise Ratio（CNR）to judge whether the WL integer ambiguity is wrong.There are only 3 degrees of freedom in all the ambiguities,therefore we fix the wrong ambiguities by the right ambiguities.We analyze the feasibility of the proposed algorithm in Gaussian noise environment.The results show all the carrier phase measurement in normal CNR environment can judge whether the WL integer ambiguity has one cycle error.The maximum carrier phase error is calculated in case we consider the multipath and other carrier phase measurement error.The probability of one cycle WL integer ambiguity error is analyzed with pseudo-range measurement error in different orders of magnitude.Field tests were carried out by using GPS short baseline data.The proposed algorithm increases the success rate of the WL integer bootstrapping ambiguity resolution algorithm from less than 1/3 to nearly 100%.
作者
刘硕
张磊
李健
LIU Shuo 1,2, ZHANG Lei 1,2, LI Jian1,2(1 School of Information and Electronics, Beijing Institute of Technology, Beijing 100081, China ;2Key Laboratory of Electronic and Information Technology in Satellite Navigation, Beijing Institute of Technology Beijing 100081, Chin)
出处
《武汉大学学报（信息科学版）》
EI
CSCD
北大核心
2018年第4期637-642,共6页
Geomatics and Information Science of Wuhan University
基金
国家自然科学基金(61101128)
国家高技术发展研究计划(2013AA122103)~~
关键词
GPS
宽巷
整周模糊度
整数引导
固定错误
GPS
wide lane
integer ambiguity
integer bootstrapping
ambiguity resolution error
