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《测量评论》2013,45(84):282-283
Abstract1. The explanation of this fundamental operation in setting up surveying instruments, as well as of the theory of the level on which it is based, is, in my opinion, not sufficiently explained in text-books. I came across the problem while lecturing on the theory of surveying instruments. Below is an extract of the notes I made on the subject, which may have a didactical interest. 相似文献
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《测量评论》2013,45(7):32-33
AbstractThe following note may be of interest to those responsible for or engaged in trigonometrical reconnaissance and observing, precise levelling, topographical mapping, and other branches of surveying where telescopes or field-glasses are used for long-distance work, especially when visibility is low. 相似文献
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AbstractIn this article the author explains how military geography information is being exploited by modern Armed Forces. In doing so he highlights some of the underlying principles of surveying and cartographic that define paper mapping, and that are still applicable in the digital era.This article reflects the personal views of Lieutenant Colonel Prain who is currently serving in the Headquarters of the Defence Geographic and Imagery Intelligence Agency. 相似文献
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AbstractAs already noted in the last instalment of this report, the whole of Monday, 16th July, was devoted to all-day visits to (i) a surveying ship of the Royal Navy, or (ii) the Royal Observatory at Hurstmonceaux Castle, or (iii) the School of Military Survey at Newbury, Berks, delegates being divided into three groups with one group going on each visit. 相似文献
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《测量评论》2013,45(97):133-137
AbstractThe object of this article is to help surveyors and computers to decide whether one of several measurements of the same quantity ought to be rejected or not. No new theories are developed, but some explanation is given as t9 how the mathematical theory of statistics may be applied to measurements made in surveying. 相似文献
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《测量评论》2013,45(78):338-348
AbstractRadar can be applied to surveying for precise measuren1ent of long lines, and as a navigational aid and position-fixing device for an aircraft performing a photographic survey. Trials of the radar method have recently been carried out in Australia using a modified “Shoran” equipment. The results of a large number of radar measurements of six distances, varying from 160 to 310 miles in length, indicate that an accuracy of 7 parts in 105 can be achieved. Equipment errors constitute the immediate limit to accuracy, but reasonable modifications would yield a figure of 2 parts in 105. Radar measurements can be completed in a fraction of the time required by normal ground survey methods, since a measurement of upwards of a hundred miles is made in a single step.As an aid to photographic surveying a straight-line track indicator actuated by data from the “Shoran” equipment has been designed and flight tested. Its performance enabled a pilot taking aerial photographs to keep the aircraft to within an average departure of less than 0.02 mile from any desired straight-line flight path. 相似文献
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《测量评论》2013,45(80):60-65
AbstractThe 200th anniversary of the publication by Murdoch Mackenzie (Senior) in May 1750 of his “Orcades, or a Geographic and Hydrographic Survey of the Orkney and Lewis Islands, in 8 maps”, is an opportune moment for a brief résumé of the contribution made by Mackenzie and his successors in the field of nautical surveying. The appearance of this work ushered in a new era in marine survey, for it was the first charting carried out in this country based on a rigid triangulation framework. The importance of this fact can further be appreciated when it is remembered that a contemporary topographic map like General Roys' famous “Map of the Highlands” begun in 1747 was little more than an elaborate compass sketch; thus under Mackenzie's influence, marine surveying at this period was ahead of its topographic counterpart. 相似文献
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《测量评论》2013,45(34):211-225
AbstractAccuracy and consistency in surveying are almost synonymous. It is true that no very great degree of precision in angular or linear measurement can be utilized in our final paper publications, even on the largest scales: all we need is an assurance that the results of further work, in the same or in adjoining areas, shall be in sympathy with antecedent measurement, so as to avoid the necessity for assigning several positions to the same point. 相似文献
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《测量评论》2013,45(3):121-127
AbstractThe preservation of health is of paramount importance to the surveyor, who often has to carry out his work in a tropical or subtropical climate, and soon, discovers that loss of time through sickness means uneconomical surveying. It is not realized by everyone that enormous casualties are still caused among modern armies by disease; the best way of illustrating this fact is to quote figures for the last thirty years. 相似文献
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《测量评论》2013,45(96):81-87
AbstractSeveral articles which deal with instruction in surveying at the university have appeared recently in the E.S.R., notably ones by P. N. Ray (xii, 89, 104–110), A. Stephenson (xii, 91, 217–222)and K. R. Peattie (xii, 94, 376–379). Particular attention is given in them to courses for engineering students. It may be of interest to readers of this Journal to hear of a survey course for geography students. Although the pattern varies at different universities, it is common to find instruction, for all geography students, in simple surveying, with practice in chain and compass surveys and the use of the plane table, while Honours students may select surveying at a late stage in the course as one of the branches of the subject in which they are to specialize. Below are set out details of a course given at University College, Ibadan, Nigeria. 相似文献
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《测量评论》2013,45(91):217-222
AbstractThe title and content of Mr. Ray's contribution to the July number of the E.S.R. entitled “Surveying Instruction at the University” is in the present writer's opinion, somewhat misleading. Obviously he is only referring to the teaching of surveying to civil engineering undergraduates and to students of such other branches of engineering as may be catered for, and does not mention the quite extensive surveying courses associated with the degrees in Geography and Mining at certain Universities. The gist of the article is confusing in that the author concludes by stating that he is “making an honest attempt to assess the merits of the surveying instruction given in the Universities of this country”, which is an admittedly worthy quest but scarcely compatible with some earlier statements such as “the long overdue overhaul of our University courses”, a statement which seems a little premature for one who is still in the stage of “honestly assessing” what is going on. 相似文献
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《测量评论》2013,45(20):350-354
AbstractMost text-books on surveying limit their discussion of the correction of vertical angles for curvature of the earth and atmospheric refraction to the correction of angles taken with a theodolite during triangulation and omit any reference to those taken with a clinometer. This is rather illogical, as in well-observed triangulation, with all vertical angles measured in both directions, no correction for these effects is necessary, whilst in plane-tabling on small scales where sketching at considerable distances is frequently employed the application of corrections for these effects is essential. 相似文献
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《测量评论》2013,45(13):400-403
AbstractIn text-books on surveying the rangefinder is usually dismissed in one sentence, which merely remarks on its inaccuracies and places in the category of scientific curios an instrument which should be most valuable to the plane-tabler in certain types of country. It is to combat this effect and to help topographers in their arduous work that these notes have been written. They are written from experience gained on topographical survey, on a scale of 1/125,000, in a tropical dependency where reduction of cost is of primary importance. 相似文献
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《测量评论》2013,45(86):347-356
AbstractWhile at first sight there appears to be considerable difference in surveying practice between American and British engineers, the underlying principles are of course the same. Perhaps the major contrast is in terminology; for example, the term transit is invariably used for the (transit) theodolite, stadia for tacheometry, spiral for transition, elevation for reduced level, whilst the telescope is plunged, not transitted. These and other differences in nomenclature are at first misleading, but are soon in regular use by the visitor to the States. 相似文献
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G. Petrie 《The Cartographic journal》2013,50(2):60-73
AbstractThe equipment available for numerically controlled plotting and draughting is reviewed and certain devices described in some detail. Several systems suited to the digitising of cartographic material exist, while the available plotters may be classified broadly into three categories—those derived from surveying and photogrammetric practice, those associated with computer technology and a group designed substantially for cartographic applications. Finally the various input and output devices associated with cartographic digitising are discussed with special emphasis on their storage capacity, speed of operation and economy. 相似文献