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1.
《测量评论》2013,45(17):138-147
AbstractWhile there is no standard method in stadia surveying of taking a set of readings for distance and altitude, the following may be regarded as the conventional, text-book method. The telescope is directed at the staff and the apparent lower hair brought to bear exactly on some convenient foot-mark. The readings of all three hairs are then taken and recorded (4.00, 5.41, and 6·83). Finally the vertical circle is read—to the nearest minute or to a fraction of a minute according to circumstances—and the result entered in the field-book (6° 31′ or 6° 31′ 20″). This method has its merits. It is straightforward and flexible and there is a simple (numerical) check on the accuracy of the staff-readings. Nevertheless it is by no means a perfect method. 相似文献
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《测量评论》2013,45(27):290-294
AbstractThe desirability of determining as accurately as possible the latitudes and longitudes of a number of points in Mauritius appears to have first appealed to the French astronomer M. L'Abbé de la Caille, who was sent to the island by the French East India Company in 1753. His observatory was situated 4,730 feet east and 2,610 feet north of Port Louis Time Ball, and in addition to determining the geographical position of this. 0bservatory (the house, later demolished, of a Mr Mabile, where Mr D'Après had made observations the previous year)—Latitude 20° 09′ 42″ S.; Longitude 55° 08′ 15″ E. of Paris—,he succeeded in effecting a triangulation of the island. Four bases were measured with wooden scales which previously had been compared with an iron toise (6.394 feet—the French fathom) approved by the Academy of Sciences, Paris; a I4-inch quadrant fitted with micrometer was used to measure the angles. 相似文献
3.
《测量评论》2013,45(30):450-457
Abstract Malaya.—The geographical positions of points in the “Primary Triangulation of Malaya”, published in 1917, depend upon latitude and azimuth determinations at Bukit Asa and on the longitude of Fort Cornwallis Flagstaff, Penang, the latter being supposed to be 100° 20′ 44″.4 E. This value was obtained by Commander (later Admiral) Mostyn Field in H.M.S. Egeria 1893, by the exchange of telegraphic signals with Mr Angus Sutherland at Singapore, Old Transit Circle. The longitude, 103° 51′ 15″.75 E., accepted for Singa- pore in order to arrive at this determination of Fort Cornwallis Flagstaff, was based upon that of an Observation Spot, 103° 51′ 15″.00 E., fixed in 1881 by Lieutenant Commander Green, United States Navy, by meridian distance from the transit circle ofMadras Observatory, the corresponding longitude of the latter being taken as 80° 14′ 51″.51 E. 相似文献
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《测量评论》2013,45(12):357-367
AbstractThe only essential difference between geodetic triangulation and any other of the fifteen “orders” of triangulation—which were once proposed, and happily rejected, at an International Conference—is that steps are taken to secure the high degree of accuracy necessary over the large areas to be covered. Some of the steps taken to secure increased accuracy may well be used to insure economy in secondary work, as for instance the use of fewer readings of a large instrument, or the use of luminous signals in conditions of poor visibility; while any surveyor may at any time have to connect his work to a geodetic triangulation, using much the same methods. 相似文献
6.
《测量评论》2013,45(70):330-344
AbstractThe late war has been responsible for many unusual situations—not the least of which was that of certain British Colonial Surv1ey Offices passing under the control of an Asiatic Invader, and it is thought that the story of one of them—the Survey Department of Malaya—will not be without interest to readers of this Review. 相似文献
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《测量评论》2013,45(11):297-303
AbstractThe Gold Coast, including that portion of Togoland which is mandated to Great Britain, comprises an area of 91,843 square miles lying between the parallels 4° 45′ N. and 11°N. and the meridians 1° 10′ E. and 3° 10′ W. The greater part of the southern area is covered with dense forest, but in the north the forest gradually opens out to more open “orchard-bush”, while in the extreme north the country consists of rolling plains covered with tall elephant-grass. 相似文献
8.
AbstractCountersection is a jointure of intersection and resection. In addition to the elementary problem of a single triangle, whereof one angle is intersecting and one resecting—sometimes known as the problem of “lining in”—, there are many others of a nature somewhat more complex. 相似文献
9.
《测量评论》2013,45(13):395-400
AbstractGeneral.—The two main causes bringing the Surveyor's work into association with that of the Town-Planning Engineer are development of new areas, arising from industrial, residential, or other necessity for expansion, and the replanning of congested or badly laid out districts in existing towns. The initiative in such schemes may come from a Local Authority, private enterprise, or public representations. 相似文献
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AbstractThe majority of readers are doubtless aware of the masterly summary of the “History of the Calendar,” written for the Nautical Almanac for 193I (pp. 734–747) by Dr. J. K. Fotheringham. Most are probably also aware that the question of Calendar Reform has been considered by the League of Nations. At the Conference on Communications and Transit of 1931, October 19, the League adopted a resolution recommending a fixed Easter, but declared that “the present time is not favourable … for considering … a reform of the Gregorian calendar.” For information on the various measures of reform proposed at Geneva the works noted below may be consulted. In the meantime, pending the coming of reform—for come it will—readers may desire to.have a summary history of the question, with a statement of a solution which is of somewhat the same nature as others which have been proposed. 相似文献
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《测量评论》2013,45(5):207-214
Abstract Artillery Survey.—Included in the term “Artillery Survey are two distinct problems, the first that of determining the “line” and “range” at which fire should be opened, and the second that of laying the gun in the required line. To appreciate these problems it. is necessary to know a little about the technique of gunnery, and for the benefit of those who have no acquaintance with the subject the following brief résumé may be given. 相似文献
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《测量评论》2013,45(41):156-159
AbstractAs Mr H. F. Rainsford (E.S.R., no. 37, vol. v, July 1940) says, the ordinary accurate survey traverse, through its “ordinariness,” has been neglected in the printed word. The technique—perfected by much practice—has been handed down by word of mouth only from father to son, from surveyor to pupil. 相似文献
13.
《International Journal of Digital Earth》2013,6(6):623-638
ABSTRACTThe capacity of six water stress factors (ε′i) to track daily light use efficiency (ε) of water-limited ecosystems was evaluated. These factors are computed with remote sensing operational products and a limited amount of ground data: ε′1 uses ground precipitation and air temperature, and satellite incoming global solar radiation; ε′2 uses ground air temperature, and satellite actual evapotranspiration and incoming global solar radiation; ε′3 uses satellite actual and potential evapotranspiration; ε′4 uses satellite soil moisture; ε′5 uses satellite-derived photochemical reflectance index; and ε′6 uses ground vapor pressure deficit. These factors were implemented in a production efficiency model based on Monteith’s approach in order to assess their performance for modeling gross primary production (GPP). Estimated GPP was compared to reference GPP from eddy covariance (EC) measurements (GPPEC) in three sites placed in the Iberian Peninsula (two open shrublands and one savanna). ε′i were correlated to ε, which was calculated by dividing GPPEC by ground measured photosynthetically active radiation (PAR) and satellite-derived fraction of absorbed PAR. Best results were achieved by ε′1, ε′2, ε′3 and ε′4 explaining around 40% and 50% of ε variance in open shurblands and savanna, respectively. In terms of GPP, R2?≈?0.70 were obtained in these cases. 相似文献
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《测量评论》2013,45(14):472-484
Abstract Choice of Beacon.—The general question as to whether luminous or opaque signals should be used in ruling triangulation has recently been discussed in the Empire Survey Review (No.9, pp. 151–2 and No. 12, pp. 335–6). It may here be summarized that opaque beacons of suitable design are sufficiently accurate and offer the considerable advantages of being immediately available for subsequent work, of requiring little or no attention, and of being visible from all directions without rearrangement. Moreover, if of the tripod or quadripod type, they need not be dismounted during occupation of the station for observing, so that 0bservations by more than one observer are not interrupted. The only occasion for using luminous beacons arises from bad visibility, whether through atmospheric haze or lack of a suitable background or through the economic necessity of completing observations at night. These conditions are not peculiar to ruling triangulation. An ”all-round” type of luminous beacon—a pressure oil lamp or a rotating mirror system—can be used for nightwork or against a dark background, but single-direction luminous beacons are necessary to overcome haze. 相似文献
15.
《测量评论》2013,45(96):87-92
AbstractVolumes of the earthwork involved along any proposed route maybe calculated from the taking of vertical cross-sections at regular intervals along the line—the spacing of the sections depending on the nature of the ground, the sections frequently being taken at points of whole through chainage and at points where cut gives way to bank and vice-versa. The process may be combined with that of slope-staking, in which case the areas may be calculated direct from the field notes, or alternatively the slope of the ground at each point considered may be shown on the drawing-board and the desired surface added, yielding in either case the cross-sectional area of cut or fill. 相似文献
16.
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
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《测量评论》2013,45(26):230-234
AbstractTHE resolutions and pious hopes (væux) passed by the International Union of Geodesy and Geophysics at Edinburgh in September 1936 have just been circulated in a formidable document of 8 pages and XXIX commandments. Of these, two affect the Cape-to-Cairo line particularly and they seem to deserve special study. The first of these, Number III—on systems of Projections—applies the meridional strips of the Transverse Mercator Projection apparently to all maps, topographical as well as cadastral. 相似文献
18.
《测量评论》2013,45(30):457-462
AbstractIn the original geodetic series in Southern Rhodesia—completed by Mr Alexander Simms in 1901—the geographical coordinates of all stations were referred to the point SALISBURYas origin. The coordinates of SALISBURY were fixed by interchange of telegraphic signals with the Royal Observatory at the Cape for longitude, combined with astronomical determinations of time, latitude, and azimuth (see Vol. III, “Geodetic Survey of South Africa”). 相似文献
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