OBSERVING WITH THE ZEISS AND WILD THEODOLITES

Abstract

RELATIVE to discussions on the Wild theodolite in the E.S.R. the following contribution considers some properties common to that instrument and the Zeiss II; perhaps to the Tavistock also, with which, however, the writer has had no experience on precise triangulation.     

电子经纬仪三坐标精密测量

与三坐标测量机相比，电子经纬仪三坐标测量法易于搬迁，且能无接触地测量大尺寸物件。但迄今为止，电子经纬仪三坐标测量法一直被认为精度太低而不能用于精密坐标测量，影响其精度的主要因素是电子经纬仪自身标定时的精度大低，为此，给出了一种新的自身标定方法，这种方法能很好地消除自身标定时的误差，且通过实验验证。     

提高建筑物沉降观测精度的方法

提出了提高建筑物沉降观测精度的方法,分析了能有效地避免观测值的粗差、i角及i角变化的误差、前后视距不等和立尺不直带来的误差影响,提高了建筑物沉降观测精度.     

THE DEVELOPMENT OF THE WILD RECTIFIERS

The paper traces the history of the Wild series of rectifiers, paying particular attention to the mechanical solutions of the Newton and Scheimpflug conditions.     

大广坝土坝放样及精度分析

本文介绍了土坝坡脚线放样方法，并对精度作了分析。     

古建筑高精度正射影像图的制作

提出了基于分层三角网的在及物体之间遮挡关系，同时引入相对控制条件，使用纹理贴面技术制作高精度正射影像的方法和实现技术。在VirtuoZo数字摄影测量软件中据此开发了相应软件模块，从而实现了香港志莲净苑大雄殿正立面影像图的制作。     

论精密水准测量的误差传播,精度估计和质量控制

本文根据统计相关理论，在进行精密水准测量的误差传播和精度估计研究的基础上，探讨了全中误差的限差和质量控制问题。根据图形相关原理，给出了计算全中误差的无偏公式。     

影响高等级全站仪水平方向测角精度的因素

就影响全站仪水平方向测角精度的有关因素作了分析，并提出内业检测和外业测量尤其是高精度的仪器或高精度的测量都应重视的因素。     

浅谈DEM的边缘精度对土石方工程计算的影响

本文介绍利用数字地面高程模型（Digital Elevation Model,简称DEM）计算土石方的方法，重点分析DEM的边缘精度对其计算结果的影响。     

HIGH PRECISION PHOTOGRAMMETRIC MONITORING OF THE DEFORMATION OF A STEEL BRIDGE

Site procedures, instrumentation, analytical methods and accuracies achieved are described for the measurement of the deformation of a military steel bridge under load in a test gantry. Some remarks concerning the advantages and disadvantages of photogrammetry as a method of industrial measurement are made.     

关于GIS属性数据逻辑运算方法的精度问题

本文对ＧＰＳ属性类别数据进行逻辑运算的误差问题进行了研究，并且针对逻辑运算的“逻辑交”，“逻辑并”和“逻辑补”等算法的误差传播和精度问题进行了分析。     

VHSR图像基于分割对象分类器性能评价

对比研究了平行六面体、最近邻分类法、最大似然法、神经网络等经典分类算法以及近年来新发展的支持向量机分类算法在基于分割对象的高分辨率遥感图像分类中的性能,详细分析了不同内积核函数对于支持向量机分类的影响。对两个试验区进行试验的结果表明,支持向量机分类算法分类精度得到明显改善,同时分类结果受参数、样本选择等影响较小,稳定性好。     

THE ADJUSTMENT OFA BLOCK OF AERIAL TRIANGULATION EVALUATED WITH THE WILD A5

Abstract

The procedure for aerotriangulation on the Wild A5 and similar plotting instruments is well known. The first overlap is set up in absolute orientation on well spaced plan and height control and successive overlaps are set up relatively, each to the previous overlap, by eliminating want of correspondence and preserving the height agreement of points falling in the common portion of successive overlaps. When each overlap is correctly set, the co-ordinates of selected points are measured on the instrument (machine co-ordinates). These co-ordinates differ from true ground co-ordinates only in origin, azimuth and scale, provided the settings and measurements are precisely done on error-free models, precisely connected together. However, such ideal conditions are never obtained, and the errors in azimp.th, scale and height datum increase with the number of overlaps added along a strip.     

ASHTECH LOCUS GPS接收机测边精度及基线处理软件的检验

本文研究ＡＳＨＴＥＣＨ ＬＯＣＵＳ ＧＰＳ接收机测边精度,同时给出一种检验其基线处理软件的有效方法。在不需要标准基线场的情况下这种方法不失为一种检测ＧＰＳ接收机精度的好途径。     

成都市GPS改扩建网的数据处理与精度分析

本文首先简要介绍了成都市平面坐标系统,分析了原坐标系统的局限性,其次详细介绍了应用GPS技术建立成都市C级控制网的工程实例,重点对改扩建的控制网布网方案、数据处理方法及精度进行了分析和研究,并对C级GPS网成果与原城市控制网成果进行了兼容性检验。     

TRIANGULATION BEACONS AND THE WILD THEODOLITE

Abstract

Following recent discussions in the E.S.R. some experiences in Sarawak may be of interest.

The argument for opaque beacons has been strengthened by the experience here of the past season, when combined day-and-night observing was carried out on the primary series, the daylight pointings being made to black-painted opaque beacons. No difference in the accuracy obtained by the two methods was noticeable in the results. Beacons were necessary in any case for the breaking down to secondary points.     

IGS精密钟差精度分析

对比了IGS官方提供的5 min和30 s间隔的精密钟差变化规律,分析了利用8阶滑动式Lagrange多项式插值和线性插值将精密钟差内插至30 s间隔的精度及可行性,得出了一些国内文献未论及的结论。     

阿深高速公路湖北省南段控制基准检测与精度分析

介绍了阿深高速公路湖北省南段控制网基准检测的外业实施和数据处理与分析,并用F检验方法对原测量成果和检测成果差异进行了显著性检验,得出了一些建议和结论。