共查询到20条相似文献,搜索用时 15 毫秒
1.
强污染单历元GPS形变信号的提取和粗差识别 总被引:6,自引:0,他引:6
阐述了小波分析技术用于强污染GPS单历元形变信号处理的基本原理及其实现方法。以含少量粗差的低信噪比形变信号为例,研究了基于Mallat分解和合成算法,分离信号趋势项并进行粗差识别的技术。采用小波软阈值降噪的方法去除强污染数据中的随机噪声,降噪效果远好于中值滤波。最后对识别的粗差信息进行线性修复,获得了令人满意的形变信号。 相似文献
2.
3.
4.
A new similar single-difference mathematical model (SS-DM) and its corresponding algorithm are advanced to solve the deformation of monitoring point directly in single epoch. The method for building the SSDM is introduced in detail, and the main error sources affecting the accuracy of deformation measurement are analyzed briefly, and the basic algorithm and steps of solving the deformation are discussed. 相似文献
5.
YU Xuexiang associate professor Ph.D Department of Resource Environment Engineering Anhui University of Science Technology Huainan China. XU Shaoquan GAO Wei LU Weicai 《地球空间信息科学学报》2003,6(4):51-56
A new similar singledifference mathematical model ( SS-DM) and its corresponding algorithm are advanced to solve the deformation of monitoring point directly in single epoch. The method for building the SSDM is introduced in detail, and the main error sources affecting the accuracy of deformation measurement are analyzed briefly, and the basic algorithm and steps of solving the deformation are discussed. In order to validate the correctness and the accuracy of the similar single-difference model, the test with five dual frequency receivers is carried out on a slideway which moved in plane in Feb. 2001. In the test, five sessions are observed. The numerical results of test data show that the advanced model is correct. 相似文献
6.
7.
基于小波变换的GPS周跳探测 总被引:5,自引:0,他引:5
概述了GPS周跳产生的原因及其探测周跳的重要性,总结了用来进行检测的常用方法,重点讨论了用小波分析来检查周跳的基本思想。并用实际的工程算例验证了该方法的可行性和有效性。 相似文献
8.
9.
10.
11.
《International Journal of Digital Earth》2013,6(1):72-82
Abstract Digital elevation model (DEM) matching techniques have been extended to DEM deformation detection by substituting a robust estimator for the least squares estimator, in which terrain changes are treated as gross errors. However, all existing methods only emphasise their deformation detecting ability, and neglect another important aspect: only when the gross error can be detected and located, can this system be useful. This paper employs the gross error judgement matrix as a tool to make an in-depth analysis of this problem. The theoretical analyses and experimental results show that observations in the DEM matching algorithm in real applications have the ability to detect and locate gross errors. Therefore, treating the terrain changes as gross errors is theoretically feasible, allowing real DEM deformations to be detected by employing a surface matching technique. 相似文献
12.
This paper describes a broad perspective of the application of graph theory to establishment of GPS control networks whereby the GPS network is considered as a connected and directed graph with three components. In this algorithm the gross error detection is undertaken through loops of different spanning trees using the “Loop Law” in which the individual components ΔX, ΔY and ΔZ sum up to zero. If the sum of the respective vector components ΩX, ΩY and ΩZ in a loop is not zero and if the error is beyond the tolerable limit (ε>ω), it indicates the existence of gross errors in one of the baselines in the loop and therefore the baseline must be removed or re-observed. After successful screening of errors by graph theory, network adjustment can be carried out. In this paper, the GPS data from the control network established as refence system for the HP Dam at Baishan county in Liaoning province is presented to illustrate the algorithm. 相似文献
13.
一种附约束的单频单历元GPS双差相位解算方法 总被引:8,自引:1,他引:8
在各类变形观测中,存在着2次观测的变形值不大及各种变形方向和大小可以比较精确预测等特点,可以把这些特征作为约束条件,对GPS单历元相位观测方程进行求解。基于以上几点,提出了一种含约束条件的单频单历元GPS相位求解算法和简单实用的模糊度搜索方法,本方法据观测值直接估计模糊度参数,并根据求出的模糊度估值进行搜索,还分析了最优解的获得和检验方法,最后用2个实例说明了该法的有效性和实用性。 相似文献
14.
Applications of graph theory to gross error detection for GPS geodetic control networks 总被引:1,自引:0,他引:1
Samwel Simon Katambi 《地球空间信息科学学报》2002,5(4):26-31
1 GraphtheoryanddefinitionsAgraphGconsistsofpoints (NODES)andlines (EDGES)connectingthesepoints .Thepointsarecallednodesandlinesareedges .Adirectedgraphisagraphinwhichtheedgescon nectingthenodesarespecified .Atreeisaconnectedgraphwithoutanyloop .Aloopisaclos… 相似文献
15.
16.
17.
弱GPS信号捕获算法的仿真实验研究 总被引:1,自引:0,他引:1
针对低信噪比环境下导航的需要,文章对低信噪比环境下弱GPS信号捕获算法进行了分析,重点对相关累加、非相关累加以及多重数据位循环相关累加捕获算法的信号处理流程和算法捕获性能进行讨论。通过特定的硬件装置获得真实的GPS信号,利用Matlab对上述3种常用的弱GPS信号捕获算法进行计算机仿真研究。根据理论分析和仿真结果可以看出,多重数据位循环相关捕获算法更适合检测低信噪比环境下的GPS信号。 相似文献
18.
为发挥北斗三频超宽巷或宽巷模糊度易于固定的优势,提出一种利用宽巷观测值的北斗单历元定位方法。首先使用载波伪距组合求解最容易固定的(0,-1,1)组合模糊度,其次基于模糊度已固定的(0,-1,1)组合观测值通过CIR方法单历元求解第二个宽巷模糊度(1,-1,0)组合模糊度。(1,-1,0)组合观测值噪声和电离层延迟综合影响最优,因此基于(1,-1,0)组合观测值进行单历元坐标解算。实验结果表明,文中提出的单历元定位方法,能够依据单历元数据最终成功解算出地面点坐标,统计精度为平面2.2cm,高程5.4cm,在满足部分领域应用要求的情况下提高效率和抗干扰能力。 相似文献
19.
雷达视线受施工机械等的间断遮挡导致部分影像产生相位奇异值,从而造成解缠错误及误差传递,简单的相关影像处理难以识别受遮挡影像。本文提出了改进的基于小波变换的信号奇异性检测方法,通过对地基SAR PS点时序相位特征进行分析,将遮挡影像识别转化为粗差探测问题;由PS点相位序列与影像位置关系,根据测区PS点相位序列的奇异点集合得到受遮挡影像集;最后将受遮挡影像剔除后得到的地基SAR监测结果与精密全站仪、水准与游标卡尺数据进行对比分析。结果表明:本文提出的方法用于受遮挡影像的识别是可行的,解决了地基SAR在实际工程应用中可能存在的影像遮挡带来的测量数据含有粗差的问题,提高了监测区域伪影像检测的效率与准确性。 相似文献