扰动质点赋值模式结构优化及序贯解法

扰动质点模型作为地球外部策略场的一种数值逼近方法，已经引起人们极大的兴趣。本文从优化模式结构出发，提出一种新的扰动质点模式构制方法，即所谓窗口移动控制法，在此基础上，推出扰动质点序贯解式，从而为解决大规模策略场逼近问题提供了有效的途径。     

THE ADJUSTMENT OF TRAVERSE NETS

Abstract

The weakest point in a straight traverse between two fixed points is well known to be in the middle. The uncertainty or p.e. perpendicular to the general direction of the traverse can be shown to be a maximum at the midpoint. Yet subsidiary traverses are usually tied in at or near this point, and consequently may show closing errors which are well in excess of what may be expected. A rigorous least squares solution would overcome this difficulty but only at the cost of a very laborious computation if the network is at all extensive. A compromise between rigour and labour can be achieved, however, which retains the major advantage of a fully rigorous solution, namely that the subsidiary traverses are not tied in at the weakest points of the main traverse system.     

THE ORTHOMORPHISM OF THE STEREOGRAPHIC PROJECTION

Abstract

When developing the argument leading to the stereographic solution of the spherical triangle and its application to field astronomy (Empire Survey Review, Vol. 2, No. 10, October, 1933, p. 226) A. J. Potter rendered a very useful service in demonstrating how proofs of the two practically useful properties of the stereographic projection can be provided along lines that demand no more than simple geometry in their development. The proof advanced for the unique property that any circle on the. sphere remains a circle in projection is at once simple and complete; but in the attempt to prove that the projection is orthomorphic in the sense that angles everywhere remain true there is the difficulty that the argument was developed for what must be regarded as a special case in that the point was located on the great circle through the origin of the projection normal to the plane of the projection. Treatment of the problem along similar lines for other points away from the central meridian does not seem to admit of such ready solution and the alternative approach suggested here, while still not demanding. anything beyond simple geometry for its understanding, affords a proof for a general case.     

THE CALCULATION OF THE HEIGHT OF KILIMANJARO

Abstract

The observations to height Kilimanjaro were made from two ground stations, Domberg (5,081·6 ft.) and Lelatema (5,323.1 ft.) and from a point called Kibo near Kaiser Wilhelm Spitze which is regarded as the highest point on the crater rim. It was originally intended to include a third ground station, Kifaru, but it was discovered that the ice cap obstructed observations between this point and the top.     

水工隧洞转点和坡度放样的简易方法

分析了转点和坡度放样的传统方法,提出了采用模型放样折线洞中线、在洞中线挂线上量测长度进行坡度放样的简易方法,提高了工作的效率。     

在推求地球外部扰动重力场中数据的采用

地球外部点的重力矢量值是由已知的全球重力位模型和各种不同方块的平均重力异常数据推求得到的。过去对选择和使用这些数据的依据不够充分,这就造成了某些随意性。本文对扰动重力在各种高度上的谱信息特征进行了分析,讨论了在一定的精度指标下各类平均异常数据区的大小范围以便为今后的实际工作提供必要的依据。     

THE MODIFICATION OF A TOPOGRAPHIC PLOTTER AND ITS APPLICATION IN THE THREE DIMENSIONAL PLOTTING OF STEREOMICROGRAPHS

A number of proposals have been put forward for the extraction of three dimensional data from a pair of electron microscope photographs taken from different angles. The methods used have, in general, been either point by point analyses or rather inconvenient. This paper shows that an existing photogrammetric plotter of topographic accuracy can, with very simple modification, be converted to give continuous plotting facilities from certain such micrographs.     

SOLUTION OF PROBLEM IN THE SUBDIVISION OF A TRIANGLE

Abstract

The division of a triangle into three lots of equal area by lines, drawn from a point within it perpendicular to the sides, appears at first sight to be a very simple problem, in which an average surveyor would experience no difficulty in performing the necessary computations for the determination of the position of the required point where the division lines meet.     

立交桥三维建模的集成方法研究

基于大比例尺航空立体像对提出三维立交桥建模方法，依据航空影像三维重建原理，从航空影像中采集出较为精确的三维立交桥轮廓线，结合立交桥设计方法，创建了基于CAD的重现点、线、多边形、体的立交桥模型，在此基础上形成了由CAD、GIS、三维影像数据集成的一种立交桥三维建模的处理方法，并提出了立交桥三维重建的层次细节模型，最后对本文方法进行了实验并获得了较好的实验结果。     

由橡胶垫连接的液化天然气储存罐沉降变形分析

利用罐体各点沉降数据,建立了回归模型和灰色系统模型,分析了各沉降点变化规律,确定了整个罐体和橡胶垫的变形规律,预测了其不均匀沉降.     

THEORETICAL MODELS OF THE ACCURACY OF DIGITAL TERRAIN MODELS: AN EVALUATION AND SOME OBSERVATIONS

This paper is an attempt to evaluate existing theoretical models for the accuracy of digital terrain models (DTM) both through a theoretical analysis and by experimental tests. In order to extend the discussion, some comments on the general form in which a DTM accuracy model should be constructed are also made and a possible solution is offered.     

虚拟压缩恢复法在向下延拓问题中的应用

阐述了基于虚拟压缩恢复法的重力场向下延拓,构造了点质量处于内部球内部、内部球外部和在内部球内外各有一个点质量三种点质量异常模型,试验结果支持基于虚拟压缩恢复法的向下延拓。     

EVALUATION OF THE COEFFICIENT OF TERRESTRIAL REFRACTION

Abstract

In two previous articles (E.S.R., vol. iv, nos. 23 and 25) it was shown that, at the time of maximum diurnal temperature in the tropics, a definite relationship exists in the lower layers of the atmosphere between the magnitude of the coefficient of terrestrial refraction at a point and the height of that point above plain level, provided the weather is fine and clear. In fact the coefficient K increases with the height h, within certain limits which are probably defined by the condensation layer.     

ON THE CLASSIFICATION OF MAP PROJECTIONS

Abstract

1. Classes and Varieties. A map projection can be considered from different points of view, each such point of view representing a “class” of projections. The classes, in their turn, are subdivided into “varieties”.     

最短路径的解法

本文介绍了一种道路网中两个节点之间最短路径的解法,具有一定的参考价值。     

IMPLICIT CONDITION EQUATIONS IN THE ADJUSTMENT OF TRIANGULATION FIGURES

Abstract

In adjusting a triangulation network it may happen that certain condition equations, of the existence of which we know a priori (by formulæ or by plotting the network point by point), cannot be established by simple inspection of the figure. This usually happens when some of the observations are missing in the otherwise continuous network. Such equations, not readily identifiable from the diagram, may be called “implicit” condition equations.     

ATLAS OF THE LATVIAN SSR

The contents of a recently published regional atlas for secondary schools in the Latvian SSR are described and critiqued. The atlas, consisting of 63 maps with explanatory text, supplemental diagrams, and photographs, was compiled by the Main Administration of Geodesy and Cartography in cooperation with the Latvian State University and the Latvian SSR Ministry of Education. Thematic coverage is divided roughly equally between physical and human/economic topics and the reviewers point out a number of shortcomings as well as innovative approaches. Translated by Elliott B. Urdang, Providence, RI 02906 from: Geodeziya i kartografiya, 1989, No. 10, pp. 42–43.     

傅科第一类回转仪运动的扰动级数分析

本文对只在陀螺力矩作用下傅科第一类回转仪的运动规律进行了扰动级数分析，推导了其运动周期公式，并与其线性解进行了比较，同时用动能法分析了该系统的稳定性．     

EXTRAPOLATION IN TIME OF REFERENCE DATA ON THE CONDITION OF NATURAL FEATURES: THE EXAMPLE OF WINTER WHEAT

The author outlines a method for extrapolating reference spectral data describing the condition of certain crops obtained for a particular point in time to periods for which reliable remote sensing data are not available. Examination of the correspondence between crop “condition classes,” identified through visual interpretation of aerial imagery, and actual yields/biomass for a number of phases of crop development of winter wheat for several crop years provides basic information for a probability matrix of the condition of a crop at times B, C, and D based on previous conditions at times A, B, and C. Translated from: Vestnik Moskovskogo Universiteta, geografiya, 1988, No. 4, pp. 73-79.