超高层建筑GPS变形监测单历元算法研究

发布时间：2018-09-16 20:45

【摘要】：超高层建筑的安全性问题是现代土木工程建设领域中所面临的重要问题之一。超高层建筑的变形监测由于其独特性，常常很难利用常规测量方法进行，GPS由于具有众多优点已经成为超高层建筑变形监测的主要方法之一，通常采用GPSRTK技术进行变形解算，近些年国内学者根据变形监测的特点提出了适用于小变形监测的单历元算法，这种方法不需要进行周跳的探测和修复，而且只需要一个历元的数据就可以解算出变形，将单历元算法应用于超高层建筑的变形监测具有重要意义。本文系统研究了GPS单历元变形解算方法，主要研究内容和贡献有： 1)详细阐述了无整周单历元算法和单历元似单差算法，通过推导从理论上证明了单历元似单差算法与无整周单历元算法是一致的。 2)针对单历元算法中需要利用首期观测坐标进行双差模糊度固定这一问题，分析推导出单历元变形解算中可以利用首期观测坐标固定双差模糊度的变形范围为0.2周（最不利情形下）。 3)利用单历元算法进行较大变形解算时需要进行模糊度搜索，为了提高模糊度搜索效率，提出了一种残差计算的快速方法，比直接解算法方程提高效率15%左右。 4)为了将单历元算法应用于连续变形监测，在分析单历元变形解算特点的基础上，提出了利用高采样率接收机和单历元算法进行连续变形监测的方法，通过试验验证了这种方法的可行性。 5)多路径效应是影响单历元变形解算精度的主要因素，在分析多路径效应机理的基础上，利用多路径效应与信号方位有关这一特点，提出利用球谐函数估计各个方位的多路径效应，其结果可以反应出多路径效应严重的信号方向。 6)针对变形监测中多路径效应难以改正这一问题，采用小波变换提取出静态变形序列中的低频部分即多路径效应对随后的数据进行改正，，可以提高精度30%左右。 7)利用Matlab进行了程序设计，编制了单历元变形解算软件，处理了某超高层建筑的试验数据并取得了较好的结果。
[Abstract]:The safety of super-high-rise buildings is one of the most important problems in the field of modern civil engineering construction. Because of its unique characteristics, it is often difficult to use the conventional surveying method for deformation monitoring of super-tall buildings. Because of its many advantages, it has become one of the main methods for deformation monitoring of super-tall buildings. Usually, GPSRTK technology is used to calculate the deformation of super-tall buildings. In recent years, according to the characteristics of deformation monitoring, domestic scholars have proposed a single epoch algorithm suitable for small deformation monitoring. This method does not need to detect and repair cycle slips, and only needs one epoch data to solve the deformation. It is very important to apply single epoch algorithm to deformation monitoring of super tall buildings. In this paper, the method of GPS single epoch deformation solution is systematically studied. The main contents and contributions are as follows: 1) the single epoch algorithm without integer cycle and the single epoch like single difference algorithm are described in detail. It is proved theoretically that the algorithm of single epoch is consistent with the algorithm of single epoch without integer cycle. 2) in the algorithm of single epoch, it is necessary to use the first observation coordinate to fix the ambiguity of double difference. It is deduced that the deformation range of double difference ambiguity can be fixed by the first observation coordinate in the deformation solution of single epoch. The range of deformation is 0.2 cycle (in the worst case). 3) the ambiguity search is needed when the single epoch algorithm is used to solve the large deformation. In order to improve the efficiency of ambiguity searching, a fast method for calculating residual error is proposed, which is about 15% more efficient than the direct solution of the equation. 4) in order to apply the single epoch algorithm to continuous deformation monitoring, On the basis of analyzing the characteristics of single epoch deformation calculation, a method of continuous deformation monitoring using high sampling rate receiver and single epoch algorithm is proposed. The feasibility of this method is verified by experiments. 5) the multipath effect is the main factor that affects the accuracy of single epoch deformation solution. Based on the analysis of the mechanism of multipath effect, Based on the characteristic that the multipath effect is related to the azimuth of the signal, the spherical harmonic function is used to estimate the multipath effect of each azimuth. The results can reflect the direction of signal with serious multipath effect. 6) it is difficult to correct the problem of multipath effect in deformation monitoring. Wavelet transform is used to extract the low-frequency part of the static deformation sequence, that is, multipath effect to correct the subsequent data. The accuracy can be improved by about 30%. (7) the program is designed by using Matlab, and the software for calculating the deformation of single epoch is developed. The experimental data of a super-tall building are processed and good results are obtained.
【学位授予单位】：清华大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU196.1;P228.4

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