Estimation of parameters in a split functional model of geodetic observations (<Emphasis Type="Italic">M</Emphasis><Subscript>split</Subscript> estimation)

The paper presents a method of estimating parameters in two competitive functional models. The models considered here are concerned with the same observation set and are based on the assumption that an observation may result from a realization of either of two different random variables. These variables differ from one another at least in the main characteristic (for example, outliers can be realizations of one variable). A quantity that describes the opportunity of identifying a single observation with one random variable is assumed to be known. That quantity, called the elementary split potential, is strictly referred to the amount of information that an observation can provide about two competitive assumptions concerning the observation distribution. Parameter assessments that maximize the global elementary split potential (concerning all observations), are called M _split estimators. A generalization of M _split estimation presented in the paper refers to the theoretical foundation of M-estimation. An erratum to this article can be found at     

The determination of potential difference by the joint application of measured and synthetical gravity data: a case study in Hungary

In an elementary approach every geometrical height difference between the staff points of a levelling line should have a corresponding average g value for the determination of potential difference in the Earth’s gravity field. In practice this condition requires as many gravity data as the number of staff points if linear variation of g is assumed between them. Because of the expensive fieldwork, the necessary data should be supplied from different sources. This study proposes an alternative solution, which is proved at a test bed located in the Mecsek Mountains, Southwest Hungary, where a detailed gravity survey, as dense as the staff point density (~1 point/34 m), is available along a 4.3-km-long levelling line. In the first part of the paper the effect of point density of gravity data on the accuracy of potential difference is investigated. The average g value is simply derived from two neighbouring g measurements along the levelling line, which are incrementally decimated in the consecutive turns of processing. The results show that the error of the potential difference between the endpoints of the line exceeds 0.1 mm in terms of length unit if the sampling distance is greater than 2 km. Thereafter, a suitable method for the densification of the decimated g measurements is provided. It is based on forward gravity modelling utilising a high-resolution digital terrain model, the normal gravity and the complete Bouguer anomalies. The test shows that the error is only in the order of 10⁻³mm even if the sampling distance of g measurements is 4 km. As a component of the error sources of levelling, the ambiguity of the levelled height difference which is the Euclidean distance between the inclined equipotential surfaces is also investigated. Although its effect accumulated along the test line is almost zero, it reaches 0.15 mm in a 1-km-long intermediate section of the line.     

山区遥感图像自动分类研究——以西南地区为例(英文)

In mountainous areas, it is the undulant terrain, various types of geomorphic and land use that make the remote sensing images great metamorphism. Moreover, due to the elevation, there are many areas covered with shadow, clouds and snow that make the images more inaccurate. As a result, it would be very difficult to carry out auto-classification of RS images in these areas. The study took Southwest China as the case study area and the TM images, SPOT images as the basic information sources assisted by the a...     

基于全站仪观测数据的三维平差模型及数据处理

建立基于全站仪多维观测数据的三维网平差模型,用VisualBasic语言编制计算程序,使其自动完成控制网的平差,解决实际应用中全站仪采集数据和成果处理中存在的问题,指导测绘生产,使全站仪更方便地用于地形控制测量、工程控制测量等测绘工程中。     

基于3S技术的矿产资源移动执法监察系统的设计与实现

针对矿产资源开采现状,提出了3S一体化的矿产资源移动执法的设计思想,探讨和分析了辽宁省矿产资源移动执法系统的系统架构与功能、工作流程,并对系统开发过程中的矿山违法信息提取关键技术进行了详细介绍。为矿产资源信息化管理提供了一种很好的借鉴模式。     

抗差卡尔曼滤波在聊城古建筑动态数据处理中的应用

古建筑在日照、风压等因素的影响下,易产生老化变形,一般会采用及时补救的方法,有时并没有分析其根本原因,本文在布设动态监控网,获得监控数据后,用抗差卡尔曼滤波对监控数据进行分析的方法,对变形方向进行预测,预测值与平差值的误差均在限差范围内,且变化方向大致相同,可以将它作为古建筑变形方向的预报,做到防患于未然。     

凸包插值算法的改进与实现

研究了凸包插值算法在n维欧拉空间构造Delaunay三角网的应用,提出了其三角剖分不惟一的重大缺陷,采用了限制区域生长法解决了这一缺陷。     

电子地图多尺度显示中“放大镜”效果的实现

"放大镜"效果是电子地图多尺度表达的形式之一,能够以更多的细节显示某个或某几个重点,而其他区域则以较少的细节表示。"放大镜"效果的实现需要从数学基础、数据组织、显示调度等多方面进行改造,针对上述几方面讨论了"放大镜"效果的实现方式,并进行了实验论证。     

海底地形数据处理与DEM生成

分析了海底DEM生成经常会遇见的问题,介绍了坐标变换、接边处理、插值加密等数据预处理方法,最终生成海底规则格网DEM。     

引黄入晋工程的桩号系统设计与应用

对于象引黄入晋工程这样的由多个混凝土建筑物紧密且“硬性”衔接而成的,高精度、超长线路工程来说,村号系统设计是一个十分重要且具有实际应用意义的问题,为了避免高斯投影误差与高程投影误差对桩号的影响,解决桩号方面由此而引起的矛盾,以及满足工程远程运营管理对桩号的要求,作者提出了在工程的勘测设计、施工和运营管理等阶段中,应分别使用设计桩号、施工桩号和管理桩号,这３种桩号就构成了超长线路工程的桩号系统。文中