BDS三频数据处理方法研究与程序实现

发布时间：2018-05-25 14:03

本文选题：三频数据组合 + 改进Kalman滤波法　；参考：《辽宁工程技术大学》2015年硕士论文

【摘要】：本文从GNSS现代化的大背景出发,以北斗二代系统为重点,以三频数据处理为主线展开论述,对相关算法进行了详尽的分析和实验,并对存在的问题进行了改进,为我国北斗导航系统的快速发展提供了一些有益的参考。GNSS现代化的重要标志之一就是三频或多频观测数据的使用,多频数据能形成更多长波长、低噪声、弱电离层延迟等特性优良的组合,从而为导航定位关键技术的解决带来新机遇。本文从以下几个方面进行了研究：1.BDS三频相位组合方面,从相位组合的定义出发分析了组合后的各项误差特性,筛选了一些全局最优解的组合系数,提出一种基于平面不等式约束法的组合系数选取法。2.BDS三频周跳探测与修复方面,研究了几种单双频法,提出一种改进的Kalman滤波法；研究了伪距相位组合法及相位无几何距离法两种三频方法,推导了周跳检测量公式,实验证明两种方法对大采样率下小周跳极为敏感；提出一种组合相位差分法,该方法在组合相位间求差,实验证明可对小至1周的周跳实现探测；提出将单频多普勒法扩展为三频法,增加了多种观测值的利用,实验结果显示对10周以上的大周跳可实现探测。3.BDS三频模糊度解算方面,研究了基于观测值域的B_Tcar法,通过逐级固定超宽巷、宽巷及原始频点模糊度,实验结果显示短基线各级模糊度可单历元固定,长基线下测站间电离层相关性变弱原始频点模糊度有数周的波动；推导了一种利用三频组合解求TEC及电离层延迟量的公式,用于改正长基线下电离层延迟量,经改正波动范围可削弱至1周；对中长基线原始频点模糊度存在噪声影响的情况,引入了小波去噪法,分析了不同小波基函数的去噪效果；提出一种基于噪声误差最小化的方法解算中长基线模糊度,推导了噪声误差最小化公式,该方法可有效降低噪声对原始频点模糊度固定的影响。4.论文最后基于MATLAB GUI开发了三频数据处理软件,对相关原理加以程序实现,增强了实用性。
[Abstract]:This paper starts from the background of GNSS modernization, focusing on Beidou second generation system, taking three frequency data processing as the main line, analyzing and experimenting the relevant algorithms in detail, and improving the existing problems. It provides some useful reference for the rapid development of Beidou navigation system in China. One of the important signs of modernization of GNSS is the use of three-frequency or multi-frequency observation data, which can form longer wavelength and lower noise. Weak ionospheric delay and other excellent combination bring new opportunities to solve the key technologies of navigation and positioning. In this paper, we study the three-frequency phase combination from the following aspects: 1.BDS, analyze the error characteristics of the combination from the definition of the phase combination, and screen the combination coefficients of some global optimal solutions. A combination coefficient selection method based on plane inequality constraint method is proposed. 2. The detection and repair of cycle slips in three frequencies are studied, several single and double frequency methods are studied, and an improved Kalman filtering method is proposed. In this paper, the pseudo-range phase combination method and phase no-geometric distance method are studied, and the cycle slip detection formulas are derived. The experimental results show that the two methods are extremely sensitive to the small cycle jump at large sampling rate, and a combined phase difference method is proposed. It is proved by experiments that the method can detect cycle slips as small as one cycle, and the single frequency Doppler method is extended to triple frequency method, which increases the use of various observed values. The experimental results show that the B_Tcar method based on observation range can be used to calculate the three-frequency ambiguity of detecting. 3. The ambiguity of ultra wide roadway, wide lane and original frequency point can be fixed step by using B_Tcar method based on observation range. The experimental results show that the ambiguity of short baselines can be fixed at single epoch, and the ambiguity of ionospheric correlation weakens between stations can fluctuate for several weeks under the long baseline, and a formula for calculating TEC and ionospheric delay by using the three-frequency combination solution is derived. In order to correct the ionospheric delay under the long baseline, the fluctuation range can be reduced to 1 week after correction, and the wavelet denoising method is introduced to analyze the denoising effect of different wavelet basis functions when there is noise effect on the ambiguity at the original frequency point of the middle and long baseline. A method based on noise error minimization is proposed to calculate the ambiguity of medium long baseline. The formula of noise error minimization is derived. This method can effectively reduce the effect of noise on the fixed ambiguity of original frequency. In the end, the software of three-frequency data processing based on MATLAB GUI is developed, and the related principle is programmed to enhance the practicability.
【学位授予单位】：辽宁工程技术大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P228.4

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