ADJUSTMENT OF A TRAVERSE BY RELAXATION

Abstract

1. The condition of least squares for survey adjustments is generally accepted as providing the best set of corrections, and the method might be more universally used were it possible to avoid the solution of as many simultaneous equations as there are independent unknowns. The method of correlatives effects a simplification where the number of conditions relating the unknowns is small, notably in Traverse Survey.     

全站仪导线坐标平差方法的探讨

本文依据误差理论 ,针对全站仪导线提出了一种合理的对其坐标观测值进行平差的方法 ,并用算例验证了该方法的正确性与可行性。     

加密导线网平差程序的设计与实现

现在生产单位对于城市建设控制网的布设，倾向于首先布设GPS控制网，然后再以GPS点作为首级控制点，进行导线网加密，全面介绍了导线加密网的平差计算，据此编写了相关处理软件，并在实际生产应用中进行了验证。     

BOWDITCH TRAVERSE ADJUSTMENT AND A MODIFICATION

Abstract

Cadastral Traversing.—For cadastral purposes traverses are now being executed with an accuracy wholly unnecessary for even large topographical scales. But since “accuracy” varies from a mile to a micron, according to the viewpoint of the observer, it is advisable to exhibit a cadastral traverse, care being taken that it is not an example of that not very uncommon occurrence in which fortuity apes precIsIon. If the accuracy of the example is somewhat unusual, it can be said with assurance that it is not very unusual.     

BOWDITCH TRAVERSE ADJUSTMENT AND A MODIFICATION: NOTES

Abstract

In the second part of the paper on this subject in the last issue (30, 483) the references to the relative angular and linear closures are rather misleading. Mr Clendinning points out that the probable angular error at a station must be considered; the mean error is clearly different.     

THE EFFECT OF ALTITUDE ON TRAVERSE ERRORS

Abstract

I. These notes are the results of following up in some detail the well-known fact that the horizontal distance between two points at altitude h is greater, by an amount proportional to h, than the distance between the corresponding points at sea-level. Traverses based on rectangular coordinates are considered, with special reference to the residual errors left after adjusting the misclosures of such traverses without first eliminating errors due to altitude.     

无定向附合导线的实用性分析

本文介绍了无定向附合导线的应用、两种平差计算的方法及精度分析 ,证明了无定向附合导线是一种可靠、实用的控制方法。     

精密导线网平面位移监测应用与分析

本文综述了某个大型工程平面变形监测的情况,用严密导线网成功地测定了平面位移,监测精度优于±3mm。     

ADJUSTMENT OF THE SECONDARY TRIANGULATION OF SOUTH AFRICA

Abstract

The Secondary Triangulation of South Africa consists of a uniform network of triangles of from 5- to 10-mile sides, enmeshed in the Geodetic and Primary Triangulations. As a rule the Primary Triangulation is rigorously adjusted by least squares, and the Secondary made to conform to it by an approximately rigorous method which was introduced into the Trigonometrical Survey in 1920 by the late Dr van der Sterr.     

监测网优化设计的必要性及内容

本文详细分析了监测网优化设计的必要性，并针对监测网的特点，叙述了监测网设计的有关问题。     

ON THE ORTHOMORPHIC PROPERTY OF SCHOLS ADJUSTMENT

Abstract

In vol. iv, nos. 29 and 30, of the E.S.R., there appeared an article by Mr. D. R. Hendrikz on the “Adjustment of the Secondary Triangulation of South Africa”. He shows that, in applying the Schols method of orthomorphic transmission to the adjustment of a secondary net to a primary triangle, the secondary sides suffer small displacements.     

FORMULAE FOR THE ADJUSTMENT OF SURVEY ERRORS

Abstract

The formulae given in this paper can be used for a station adjustment at a trigonometric station and also for the adjustment of errors in a level survey. As applied to levelling, the problem consists in finding the most probable values of the reduced levels of a number of points where the observed level differences between the points are not consistent with each other. It can be shown that the required values of the reduced levels are those which reduce the sum of the squares of the residual errors to a minimum, where the residual error is defined as the difference between the calculated and observed levels.     

THE ADJUSTMENT OF A FIRST-ORDER LEVELLING NETWORK

Abstract

In the E.S.R. January and April numbers of 1955, Vol. xiii, Nos. 95 and 96, Mr. Hsuan-Loh Su described the “Adjustment of a Level Net by Successive Approximations and by Electrical Analogy”. It does not seem to be as generally known as it should be that the rigid least square solution can be greatly simplified by utilizing the electrical analogy and solving by Kirchhoff's method. The method as detailed below has been in use for over 40 years.     

SOME NOTES ON THE ADJUSTMENT OF TRAVERSES

Abstract

It has now become a truism that angles in traverses are observed with a far greater accuracy than the sides, and this applies to all categories of traverse work: precise, transit-and-tape, tacheometric traverses, etc. The result of this is that the effect of angular errors on misclosures in co-ordinates is sometimes so small when compared with that of linear errors that it may be considered as negligible.     

多元p－范极大似然平差

本文详细推导了在概括平差函数模型下多元ｐ－范极大似然平差的基础方程以及求解参数估值的计算公式。本文提出的平差方法是一种包含最小二乘法，Ｌ１、Ｌｐ（ｐ＞１）最小平差法的更一般的方法。它只需对观测误差母体作单峰、对称的假设。此方法在给出位置参数、尺度参数的估值的同时，还能对误差母体分布作出估计     

THE ADJUSTMENT OF TRIGONOMETRICAL LEVELS AND THE EVALUATION OF THE COEFFICIENT OF TERRESTRIAL REFRACTION

Abstract

This paper is written primarily with the object of ascertaining how other Colonies and Dominions deal. with the adjustment of their trigonometricallevels; further, since the greater part of Nigeria is now covered by a framework of levels of primary accuracy it is of interest to examine the results. Moreover, the evaluation of the coefficient of refraction, and from it the temperature lapse-rate, is of some importance in view of the recent publication of the War Office Aneroid Tables. These tables are based on a standard lapse-rate of temperature.     

THE APPLICATION OF THE GAUSS METHOD OF COLLIMATION TO THE ADJUSTMENT OF SURVEY INSTRUMENTS

Abstract

Gauss's method of collimation is usually given scant attention in survey text-books. The following notes are based on experiments carried out at Accra in making a collimation base, the collimator being a Watts 2I-inch self-adjusting level fitted with a parallelplate micrometer.     

THE HEIGHT ADJUSTMENT OF A SINGLE STRIP

This note represents an extension of some earlier work on the plan adjustment of a fully controlled strip (Thompson, 1967). A similar method was developed for the height adjustment. Unlike other adjustment methods using polynomials, both plan and height adjustment formulae are very simple, so that adjustment can be rapidly carried out by hand computation.