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《测量评论》2013,45(20):354-358
Abstract 6. Further Expansions.—Equations (4.3) and (5.5) enable a computer to transform coordinates from the Cassini projection to the Gauss projection without recourse to geographical coordinates. If applied to one or two points, no doubt these equations would be quite satisfactory; but if applied to 100,000 points their use would be laborious and it would be difficult to adapt them to machine computing. 相似文献
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《测量评论》2013,45(12):330-335
AbstractI. 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. 相似文献
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《测量评论》2013,45(65):131-134
Abstract1. In geodetic work a ‘Laplace Point’ connotes a place where both longitude and azimuth have been observed astronomically. Geodetic surveys emanate from an “origin” O, whose coordinates are derived from astronomical observations: and positions of any other points embraced by the survey can be calculated on the basis of an assumed figure of reference which in practice is a spheroid formed by the revolution of an ellipse about its minor axis. The coordinates (latitude = ?, longitude = λ and azimuth = A) so computed are designated “geodetic”. 相似文献
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《测量评论》2013,45(38):481-495
Abstract1. Computation of a minor triangulation as if it were executed on a plane surface of course ignores spherical excess, an omission not strictly rigorous so far as azimuths are concerned. Further the reduction of such a triangulation to a system of plane coordinates again assumes that the earth's surface is a plane. 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
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《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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Abstract Azimuth.—The method was that of star altitudes in the prime vertical, except at X. 34 where hour angles on the P.V. were observed. At B.P. 79 and 99, NE. Terminal, and X. 12 and 34, the measures were made by Major Godfrey-Faussett or Capt. Taylor with the 8-inch C.T. & S. micrometer theodolite; and at all other stations by Capt. Taylor with the Tavistock theodolite Y. 2304. 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
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Abstract1. Some Preliminary Considerations.—Let it be supposed that an iceberg is captured by an ice-field. It will be assumed that the field can be packed, either by opposing currents or by pressure against a land mass on one side. Compared with the vertical dimension of the berg the thickness of the field will be comparatively small. 相似文献
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Abstract Scale Correction Factor at a Point in Terms of X and Y.—Let dσ be a small line element of the curve ACB on the plane and ds the corresponding line element on the spheroid. 相似文献
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《测量评论》2013,45(10):206-221
Abstract4.3. Having found s we may proceed to obtain the coordinates of the air station. This is the vertex of a pyramid, the base edges being of lengths a, b, c and the opposite edges measuring u, v, w respectively. Let h be the distance of the vertex from the plane of the base, and suppose d, e1 e2, e3 are respectively twice the areas of the base and of the oblique faces in order. 相似文献
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Richard A. Snay 《Journal of Geodesy》1990,64(1):1-27
The North American Datum of 1983 (NAD 83) provides horizontal coordinates for more than 250,000 geodetic stations. These coordinates were derived by a least squares
adjustment of existing terrestrial and space-based geodetic data. For pairs of first order stations with interstation distances
between 10km and 100km, therms discrepancy between distances derived fromNAD 83 coordinates and distances derived from independentGPS data may be suitably approximated by the empirical rulee=0.008 K0.7 where e denotes therms discrepancy in meters and K denotes interstation distance in kilometers. For the same station pairs, therms discrepancy in azimuth may be approximated by the empirical rule e=0.020 K0.5. Similar formulas characterize therms discrepancies for pairs involving second and third order stations. Distance and orientation accuracies, moreover, are well
within adopted standards. While these expressions indicate that the magnitudes of relative positional accuracies depend on
station order, absolute positional accuracies are similar in magnitude for first, second, and third order stations. Adjustment
residuals reveal a few local problems with theNAD 83 coordinates and with the weights assigned to certain classes of observations. 相似文献
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Laser ranging to Starlette from April 1983 to April 1984 has been used to determine a coordinate set, UASC.ST1, of laser reference
points for 18 tracking stations. The coordinates were derived by application of the least-squares data reduction procedure
in a simultaneous solution along with geodynamic parameters for 49 near consecutive 5–6 day arcs. Comparisons with the University
of Texas station coordinates,LSC 8112 andLSC 8402, and theRGO, Herstmonceux, coordinates,RGOSC.LG2, reveal consistency to near 30 cm in each coordinate. Furthermore, the translation vectors of the comparisons are not significantly
different from zero indicating consistency in the implied origins of the systems.
The period of analysis included seven occasions in which STARLETTE was tracked near simultaneously by three or four laser
stations in North America. Using the short arcs as reference frameworks, station coordinates were determined by application
of two contrasting methods, namely, a multi-arc simultaneous analysis and a weighted mean of the individual pass solutions.
The former compared more favourably with baselines from the long-arc solution with anRMS error of near 16 cm. Comparison against theLSC 8402 coordinates confirmed that baselines accurate to within 15 cm can be achieved by satellite laser ranging to Starlette. 相似文献