ISSN:0039-6265    

DOI:10.1179/sre.1963.17.127.2

出版商:Taylor&Francis    

年代:1963

数据来源: Taylor

摘要:

AbstractThe showing of the relief of the ground is one of the most important features of a topographical map, and map makers have for centuries sought to improve the method of depiction. One of the major problems confronting the Directorate of Overseas Surveys is this depiction of relief; a problem aggravated by lack of relief information other than the effect produced by stereoscopic examination of air photographs and the heights of triangulation or tellurometer traverse points. Solutions of the problem are restricted by the fact that speed of production is always of the first importance when considering methods in the Directorate.

ISSN:0039-6265    

DOI:10.1179/sre.1963.17.127.3

出版商:Taylor&Francis    

年代:1963

数据来源: Taylor

摘要:

AbstractThe filling in of any new map with names of places, rivers and other physical features presents two main problems, which are: (1) what names to include, and (2) how to spell them. The appropriate solution of either problem will depend to some extent upon the purposes for which the map is compiled.

ISSN:0039-6265    

DOI:10.1179/sre.1963.17.127.11

出版商:Taylor&Francis    

年代:1963

数据来源: Taylor

摘要:

AbstractWith a view to obtaining a more trustworthy record of tidal movements, it was decided by the Public Works Department of the Hong Kong Government that a second permanent tide gauge was desirable in order to provide a check on results obtained from the existing gauge situated in Victoria Harbour. The reliability of the results obtained from the existing gauge was subject to some doubt due to the abnormal conditions prevailing in the Harbour—a rather narrow and shallow channel in which extensive reclamation works have taken place. A site for the new tide gauge was thus chosen well away from the harbour, on the coast of Lan Tao Island, and a gauge of the automatic recording type was duly installed on the Chi Ma Wan Prison Pier in February, 1960.

ISSN:0039-6265    

DOI:10.1179/sre.1963.17.127.15

出版商:Taylor&Francis    

年代:1963

数据来源: Taylor

摘要:

AbstractThe sources of error in systems of constrained centring are analysed and the likely magnitudes of the component errors determined from tests. The propagation of systematic error caused by target eccentricities is examined and a method proposed to eliminate this effect in traversing.

ISSN:0039-6265    

DOI:10.1179/sre.1963.17.127.22

出版商:Taylor&Francis    

年代:1963

数据来源: Taylor

摘要:

AbstractAll angles and linear dimensions required for setting out a clothoid transition curve by any of the possible field methods can be related to each other by factors having the general form (1−kversnψ) or (1±kexsecnψ), whereψis the slope angle andkandnare constants which differ for each element and are so chosen that throughout the rangeψ= 0 toψ= 50°no computed angle is in error by as much as 1″of arc and no linear dimension by more than 1 part in 17,000 in the worst case.

ISSN:0039-6265    

DOI:10.1179/sre.1963.17.127.35

出版商:Taylor&Francis    

年代:1963

数据来源: Taylor

摘要:

AbstractIn 1957 Dr. (then Mr.) T. L. Wadley, of the Telecommunications Division of the Council of Scientific and Industrial Research of South Africa, visited the United Kingdom to carry out trials on the Ridgeway and Caithness Bases of a new and quite revolutionary system of micro-wave distance measurement. Whilst hints of this new system had been circulating some two years earlier—it was, in fact, mentioned at the 1955 Commonwealth Survey Officers—Conference—no real details had been released previously. Dr. Wadley also gave a lecture at the Royal Geographical Society which was attended by most of the leading surveyors in the country. The year 1957 can therefore be looked upon as a milestone in survey history, and it was also in that year that the first Tellurometer Systems were produced commercially and became available to the surveyor. In the same year the first Tellurometer training course was organized, and it was after a four-day course—the week was cut short because the Monday was August Bank Holiday—that a team from the Directorate of Overseas Surveys set out to carry out the now well-known Isiolo to Malindi traverse in Kenya.

ISSN:0039-6265    

DOI:10.1179/sre.1963.17.127.45

出版商:Taylor&Francis    

年代:1963

数据来源: Taylor

摘要:

AbstractIn an earlier issue of theEmpire Survey Review(xvi,123, 208), formulae for the coordinates of two species of Transverse Mercator projection of the spheroid were given in closed form in terms of Jacobian elliptic functions. The present paper gives formulae for scale and convergence in the same two projections.

ISSN:0039-6265    

DOI:10.1179/sre.1963.17.127.49

出版商:Taylor&Francis    

年代:1963

数据来源: Taylor

摘要:

AbstractWhen making repeated measurements of a quantity it is often useful to be able to obtain a quick estimate of the standard error of the observations to ascertain whether they conform to a specified standard of accuracy. Calculation of the standard error by either Bessel's or Peters' method is a tedious process under field conditions and may consume valuable observing time. An alternative procedure, well known to statisticians, is to use the range of a sample,i.e.the difference between the greatest and least values of a set of observations, to provide an estimate of the standard error. On the assumption that the errors are normally distributed, it is possible to derive a theoretical distribution of the ranges of samples of various sizes in terms of their standard deviations. The mathematical derivation can be found in standard statistical texts,e.g.M. G. Kendall,“The Advanced Theory of Statistics”, Vol. I. The quantitydn=E(w/σ), that is, the expected rangewin terms of the standard deviationσ, for samples of sizenis tabulated forn= 2(1) 1000 in“Tables for Statisticians and Biometricians”, Part II, ed. K. Pearson. For our purposes we require, as multipliers of the range, the quantities 1/dnand 1/dn√nto give the standard error of a single observation and of the mean respectively, and these are tabulated below forn= 2(1)20(5)40, together with 0·6745/dnand 0·6745/dn√nto give the corresponding probable errors.

ISSN:0039-6265    

DOI:10.1179/sre.1963.17.127.51

出版商:Taylor&Francis    

年代:1963

数据来源: Taylor

ISSN:0039-6265    

DOI:10.1179/sre.1963.17.127.52

出版商:Taylor&Francis    

年代:1963

数据来源: Taylor