三频GPS周跳探测与修复方法研究

发布时间：2018-05-24 19:03

本文选题：GPS + 多频数据组合　；参考：《长安大学》2017年硕士论文

【摘要】：GPS、GLONASS、Galileo、Beidou等全球卫星导航定位系统“现代化计划”的不断推进和改善,多频率下的数据组合由于其具有更多优良特性而被越来越广泛的应用。其中,在周跳探测与修复过程中,多频数据通过多种不同方式组合所形成的组合检验量相比于传统单、双频周跳检验量,其探测精度更高。本文在采用实例实现GPS传统单、双频周跳探测方法基础上,结合多频数据组合波长更长、噪声更小、电离层影响更小这些优良特性,探究了两种新的三频GPS数据组合下的周跳探测和修复方法:无几何相位组合结合多项式拟合频间单差法和伪距相位组合法。无几何相位组合结合多项式拟合频间单差法中,选用了两组最优无几何相位法组合(1,1,-2)、(1,-2,1),虽然在只使用这两个组合的情况下几乎能探测出所有发生的周跳,但是无法做到各基础载波上周跳的分离,因此本文在传统无几何相位组合法基础上,结合了多项式拟合法拟合GPS三个频率之间的单差值,共可形成4组方程,并且任意三组线性无关,这样两种方法的结合使用不仅能顺利地探测出组合周跳,还能实现基础周跳的分离。实验结果表明该方法适用于采样间隔较小的高采样率数据下的周跳探测与修复,并且取得了比较理想的探测效果。不足之处在于,这种方法会引入不敏感周跳,增加了周跳漏探的概率。为了避免这种情况的发生,本文在双频伪距相位组合法基础上进行了改进,形成了能适用于三频数据周跳探测的伪距相位组合法。文中分析了该方法构造周跳检验量时的优选方法,在此基础上针对不同伪距噪声选取了相应最优组合,并采用0.3m伪距噪声下的(0,1,-1)、(-3,1,3)和(4,-8,3)组合从单频率、多频率、不敏感周跳三个方面进行具体实例实验,结果表明使用伪距相位组合法可以实现1周及1周以上周跳的探测与分离,且当伪距精度越高时,此方法的可靠性也会大大提高;当观测数据的采样率较高,且可忽略历元间电离层延迟变化时,针对不同的伪距观测噪声,以周跳估值标准差最小为原则,选用最优伪距相位组合可以正确探测和修复三频非差观测数据中发生的所有周跳,避免了不敏感周跳的引入。
[Abstract]:With the advancement and improvement of the "modernization plan" of GPS GLONASS GLONASS GalileoN Beidou, the data combination with multiple frequencies has been more and more widely used because of its more excellent characteristics. In the process of cycle slip detection and repair, the detection accuracy of multi-frequency data is higher than that of traditional single-frequency and dual-frequency cycle slips, which is formed by the combination of multi-frequency data in a variety of different ways. In this paper, on the basis of the traditional single-frequency and dual-frequency cycle slip detection method of GPS, combined with the advantages of longer wavelength, less noise and less ionospheric influence of multi-frequency data, In this paper, two new methods of cycle slip detection and repair for tri-frequency GPS data combination are studied: the method of single difference between frequencies and the method of pseudo-range phase combination without geometric phase combination combined with polynomial fitting. Two groups of optimal geometric phase free method are selected in the combination of geometric phase combination and polynomial fitting single frequency difference method, although almost all cycle slips can be detected under the condition that only these two combinations are used. However, it is impossible to separate the fundamental carriers from last week hopping. Therefore, based on the traditional geometric phase combination method and the polynomial fitting method to fit the single difference between the three frequencies of GPS, four sets of equations can be formed. The combination of the two methods can not only detect the combined cycle slips smoothly, but also realize the separation of the fundamental cycle slips. The experimental results show that the proposed method is suitable for cycle slip detection and repair of high sampling rate data with small sampling interval, and a better detection effect is obtained. The disadvantage is that this method can introduce insensitive cycle jump and increase the probability of cycle slip detection. In order to avoid this situation, a pseudo-range phase combination method, which can be used for cycle slip detection of three-frequency data, is developed based on the dual-frequency pseudo-range phase combination method. In this paper, the optimal selection method for constructing cycle slip test quantity is analyzed. On the basis of this, the corresponding optimal combination is selected for different pseudo-range noise, and the combination of single frequency and multi-frequency is adopted under the noise of 0.3m pseudo-range. Experiments on three aspects of insensitive cycle slip are carried out. The results show that the pseudo-range phase combination method can be used to detect and separate the pseudo-range slip in one cycle and one week, and the reliability of the method will be greatly improved when the precision of pseudo-range is higher. When the sampling rate of observed data is high and the variation of ionospheric delay between epochs can be neglected, the minimum standard deviation of cycle slip estimation is taken as the principle for different pseudo-range observation noises. The optimal pseudo-range phase combination can correctly detect and repair all cycle slips occurring in tri-frequency nondifferential observation data and avoid the introduction of insensitive cycle slips.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P228.4

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