动态定位自适应滤波解的性质   总被引：21，自引：4，他引：21  

杨元喜 《测绘学报》2003,32(3):189-192

自适应抗差滤波具有控制观测异常及状态方程信息异常干扰的能力。着重研究自适应滤波解的性质。首先推导了动态自适应滤波与经典Kalman滤波解的解差，继而给出了状态向量估值的数学期望和均方误差，并分析了在自适应因子调控下解的偏差和均方误差的变化规律。由状态解向量的数学期望和均方误差的表达式可以看出，自适应因子能够控制状态异常对状态估值和均方误差的影响。  相似文献   

水下无源导航系统仿真匹配算法研究   总被引：15，自引：1，他引：15  

张飞舟  侣文芳  晏磊  葛远声 《武汉大学学报(信息科学版)》2003,28(2):153-157

针对水下无源导航(地形辅助导航)系统的特点，充分利用各种海洋地理特征传感器获取信息，进行数据预处理、算法分析、性能评估，然后进行智能数据融合，进而完成水下无源导航系统模块化的仿真设计，为水下无源导航系统的进一步研究提供可行的方法和技术。仿真结果表明，采用水下地形匹配辅助导航，能够有效地修正惯导误差达到设计要求，为真实海洋环境下的精确导航提供可靠的技术依据。  相似文献   

GPS-measured land subsidence in Ojiya City, Niigata Prefecture, Japan   总被引：1，自引：0，他引：1  

Hiroshi P. Sato  Kaoru Abe  Osamu Ootaki 《Engineering Geology》2003,67(3-4):379-390

Land subsidence caused by compression of clay layers in Ojiya City, Japan was measured by global positioning system (GPS) between 1 April 1996 and 31 December 1998.

Three baselines were selected in and around the city, and height difference on a WGS-84 ellipsoid was measured by GPS on each baseline. The ground at the GPS station in the city subsides and rebounds 7 cm every winter and spring, respectively. Measurement accuracy was 9.5 mm standard deviation. Ground water level was observed at a well near the GPS station. Regression analysis between total strain, calculated as ratio of the height difference displacement to the total thickness of the clay layers, and the layers' effective stress change with ground water level change gave good correlation. The slope of regression line 7.0×10⁻¹¹ m²/N was obtained as an average apparent coefficient of volume compressibility of the layers.  相似文献   

等比例尺放大法实现遥感图像精确定位     

何立  马轮基  莫伟华 《气象研究与应用》2003,24(1):55-57

介绍一种卫星遥感图像定位方法——等比例尺放大法,该方法可以实现遥感图像的精确定位,满足遥感产品制作与服务的需要。此外,还具体介绍了如何利用VC语言实现等比例尺放大法图像定位。  相似文献   

GPS长距离和多测段定位中广播星历的改进方法   总被引：2，自引：0，他引：2  

王解先  朱文耀 《测绘学报》1997,26(2):140-147

本文分析了广播星历误差对ＧＰＳ长基线和多测段定位结果的影响，由此提出了旨在减弱卫星轨道误差对于相对定位精度影响的一种简便而又实用的方法，即先按卫星运动的力学模型建立状态方程，其初始状态向量由某组广播星历得出，由每组广播星历建立观测方程，由数值积分得出的参考轨道由广播星历ｔｏｅ时刻的位置和速度观测值的最小二乘平差所得的改正后的轨道，不仅可消除各组广播星历间的不一致性，而且其精度也高于任何一组广播星历  相似文献   

应用砼的流变性计算砼的灌注参数          下载免费PDF全文

张泽业 《探矿工程》1996,(3):12-13

应用流体力学、流变学的理论，方法和施工实测数据，建立水下灌注理导管埋深，砼在灌注系统的流动阻力与导管内附加砼柱间的数学表达式，以指导水下灌注施工在最优灌注参数下进行。  相似文献   

地热井井位确定研究——以豫煤二队院内地热井为例   总被引：2，自引：0，他引：2  

阎留运  徐九儒 《中国煤田地质》2004,16(1):22-25

通过对龙门地热田地质构造、地下水运动特点及规律的研究，提出了在地热田内寻找地下热水的富水靶区，并推算了其范围。又以地面调查、地面电法等手段进行了验证，确定了地下热水富水带的具体位置及地热井施工井位，一次成功地打中千米以下地热水的富水区，为地热田内寻找、开发地下热水总结了经验，丰富了深井及地热田找水的理论。  相似文献   

GPS广播星历参数拟合算法   总被引：25，自引：2，他引：25  

崔先强焦文海  贾小林尹豫疆 《测绘学院学报》2004,21(4):244-246

介绍了GPS广播星历参数的最小二乘估计方法。推导了相应的计算公式。计算结果表明。文中给出的公式是正确的，其拟合精度以用户距离误差(URE)示时，对预报轨道的损失小于1cm。  相似文献   

A new approach of single epoch GPS posi- tioning for landslide monitoring     

刘根友  朱耀仲  周蓉生 《地震学报(英文版)》2005,18(4):427-434

Introduction China is a country with many landslides and debris flows. These disasters bring out a large amount of losses of life and property. It is significant to predict landslide incident by monitoring the deformations of these landslides. At past, triangulation and trilateration are traditional tools, but it is very difficult for them to realize real-time monitoring, and it is more dangerous for obser- vation workers when the deformation becomes larger. Because of many advantages such as…  相似文献   

A Possible Detection of the 26 December 2004 Great Sumatra-Andaman Islands Earthquake with Solution Products of the International GNSS Service   总被引：1，自引：0，他引：1  

J. Kouba 《Studia Geophysica et Geodaetica》2005,49(4):463-483

The main goal of this work is to critically review the IGS solution products and Precise Point Positioning (PPP) in order to demonstrate their potential to contribute to studies of large earthquakes such as the one that devastated Southeast Asia on December 26th, 2004. In view of a possible detection of the Mw 9.0 Sumatra-Andaman Islands Earthquake of December 26, 2004, position solutions, ranging from intervals of years to one second, of four International GNSS Service (IGS) stations within 3000 km of the epicenter were examined. The IGS combined, cumulative solution product (IGS04P51), consisting of epoch and station velocity solutions and based on data spans of several years prior to the earthquake, was used as a reference. Four IGS combined weekly position solutions (igs04P1301-4), two weeks before and after the earthquake, were utilized for the weekly solution resolution. PPP static and kinematic solutions with IGS Final combined orbits and clocks were used for the mean daily and instantaneous 5-min and 1-sec epoch solutions, respectively. The most significant changes, detected by both weekly and daily solutions occurred in longitude. The nearest IGS station ntus, about 1000 km east of the epicenter, moved westward about 15 mm, while the more distant Indian station iisc (∼ 2300 km NW from the epicenter), shifted about 15 mm eastward. In spite of position errors caused by interpolation of the 5-min IGS clocks, the 1-sec solutions, based on separate data sets, available only for two stations (iisc, dgar), still showed seismic surface waves, in particular at the Indian station iisc. Precise daily IGS combined polar motion and length-of-day products, after correcting for the atmospheric effects, also likely detected, statistically significant, anomalistic excitations on December 26, 2004 that could be caused by this great earthquake.  相似文献