共查询到20条相似文献，搜索用时 15 毫秒
1.
《测量评论》2013,45(21):413-417
AbstractPrior to the year 1931 there was no systematic training of Africans for land survey work in Northern Rhodesia, and those natives then in the employ of the Survey Department as assistants to the European surveyors in the field were no more than “capitaos”. Asurveyor, after his arrival in the colony, usually had to find his own native assistant, or chainman, and any native who appeared to have a commanding manner with his fellows, and who was clean and respectful, was eligible for the position. Preference in some cases was usually given to natives who had completed service in the native regiment or police, for their early training had taught them to obey orders, to conduct themselves well, and to control other natives. 相似文献
2.
Abstract The transition and restructuring process of urban South Africa are currently in the phase of identifying land development objectives. These objectives aim to integrate previously segregated areas through integrated development plans. This research aims firstly to identify and describe the historical development of the spatial form and structure of the secondary city and capital of the Northern Province, Pietersburg and its dispersed peripheral towns. Supervised classification of SPOT HRV multispectral imagery is used to support the theoretical explanation. Images from an airborne digital Kodak DCS 420 camera are used to provide training sites in the pre‐classification stages, and also provide field data to the process of post‐classification accuracy assessment. Secondly, SPOT HRV imagery is applied to identify the stark contrast in urban development between the city of Pietersburg and its surrounding former homeland towns. Both built and natural environmental aspects are investigated. In conclusion benefits and problems of assessing urban morphology and development in a developing country by means of a combination of satellite imagery and digital aerial photography are discussed. 相似文献
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4.
《测量评论》2013,45(15)
AbstractWith regard to the cadastral maps of New Zealand it may be observed that the function of any particular class of map in this Dominion depends very much on whether it is a representation of the area, boundaries, and ownership of freehold lots, a subdivision of Native land, or one of the various leasehold tenures of Crown land. 相似文献
5.
AbstractThe proof of the attraction of a uniformly thin vertical block in the last issue (No. 24, p. 87) does not appear as satisfactory as the textbook would suggest. It is proposed to attempt here a more direct explanation, independent of substitutional expedients. 相似文献
6.
AbstractThis explains the formation of the Ordnance Survey of Northern Ireland as a separate institution in 1921, when it took over the map series which until that time had been part of the Ordnance Survey (U. K.) responsibility. As happened with many mapping organisations, replanning and reorganisation took place after 1945; this included a triangulation for Northern Ireland to provide a basis for a new Irt"sh Grid, and the introduction of the 1:1250 scale for major urban areas.The technical problems of reproduction and revision are then considered, and details given for each of the main series. 相似文献
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8.
J. C. Owens 《Journal of Geodesy》1968,42(3):277-291
The development of lasers, new electro-optic light modulation methods, and improved electronic techniques have made possible
significant improvements in the range and accuracy of optical distance measurements, thus providing not only improved geodetic
tools but also useful techniques for the study of other geophysical, meteorological, and astronomical problems. One of the
main limitations, at present, to the accuracy of geodetic measurements is the uncertainty in the average propagation velocity
of the radiation due to inhomogeneity of the atmosphere. Accuracies of a few parts in ten million or even better now appear
feasible, however, through the use of the dispersion method, in which simultaneous measurements of optical path length at
two widely separated wavelengths are used to determine the average refractive index over the path and hence the true geodetic
distance. The design of a new instrument based on this method, which utilizes wavelengths of6328 ? and3681 ? and3 GHz polarization modulation of the light, is summarized. Preliminary measurements over a5.3 km path with this instrument have demonstrated a sensitivity of3×10
−9
in detecting changes in optical path length for either wavelength using1-second averaging, and a standard deviation of3×10
−7
in corrected length. The principal remaining sources of error are summarized, as is progress in other laboratories using
the dispersion method or other approaches to the problem of refractivity correction. 相似文献
9.
《The Cartographic journal》2013,50(2):90-94
AbstractSome problems of land use map production are analysed in the general context of colour cartography by a Senior Lecturer in Geography, King's College, University of London, who is also Director of the Second Land Utilisation Survey of Britain. 相似文献
10.
none 《The Cartographic journal》2013,50(2):191-201
AbstractVegetation and rural land use show some of the greatest variety both in what and in how they are depicted on topographic maps. This paper discusses the various approaches that have been adopted to the selection of information to be shown on non-specialist maps. It also looks at the different ways in which vegetation and rural land use are depicted on a range of published map. 相似文献
11.
《测量评论》2013,45(96):70-75
AbstractThe following paper describes some of the results obtained on it, tour of the Katsina and Kano Provinces of Northern Nigeria between November 1953 and February 1954. The purpose of the tour was to obtain latitudes and longitudes by astronomical observations for air photo mapping control in the northern parts of these provinces where triangulation is not available. The area is mostly flat and sandy. 相似文献
12.
《International Journal of Digital Earth》2013,6(1):50-64
Abstract Changing environmental and socio-economic conditions make land degradation, a major concern in Central and East Asia. Globally satellite imagery, particularly Normalized Difference Vegetation Index (NDVI) data, has proved an effective tool for monitoring land cover change. This study examines 33 grassland water points using vegetation field studies and remote sensing techniques to track desertification on the Mongolian plateau. Findings established a significant correlation between same-year field observation (line transects) and NDVI data, enabling an historical land cover perspective to be developed from 1998 to 2006. Results show variable land cover patterns in Mongolia with a 16% decrease in plant density over the time period. Decline in cover identified by NDVI suggests degradation; however, continued annual fluctuation indicates desertification – irreversible land cover change – has not occurred. Further, in situ data documenting greater cover near water points implies livestock overgrazing is not causing degradation at water sources. In combination of the two research methods – remote sensing and field surveys – strengthen findings and provide an effective way to track desertification in dryland regions. 相似文献
13.
《测量评论》2013,45(17):158-162
AbstractThe Northern Rhodesia Survey Department recently carried out a series of measurements of certain cross-sections of the Zambezi in the vicinity of Livingstone. The stretch of river over which the above were made is that known as the Regatta Course and extends between the top of Loando or Long Island downstream to the mouth of the Maramba River. This stretch is about three and a half miles southwest of Livingstone and two to four miles upstream from the Victoria Falls. 相似文献
14.
《测量评论》2013,45(70):351-356
AbstractThe method of checking reduction of normal equations which will be described below was first devised by the present writer when he had to adjust in one set the whole of the Southern Block of the Major Triangulation of Palestine, involving 114 equations of condition. This method. proved to be so useful and. efficient that, when subsequently adjusting the Northern Block of the same network (117 condition equations in simultaneous adjustment), the advisability of its application was obvious. Finally, in war time, the adjustment in one set of 65 condition equations of the Northern part of the Transjordan Primary Triangulation observed by the Army, equally underwent self-checking by the same method and proved a complete Success. 相似文献
15.
Abstract Much of the human dimensions of environmental change research emphasize the mapping and modeling of land use and land cover patterns over space and time, and the linkages between people, place, and environment as proximate and distal forces of landscape dynamics. Spatial digital technologies, framed within a GIScience (GISc) context, figure prominently in the characterization of land use and land cover through remote sensing technologies, and in the assessment of social and demographic factors and local and regional site and situation considerations achieved through global positioning systems, data visualizations, and spatial and statistical analyses. Here, we describe some fundamental approaches for linking data across thematic domains, essential for the study of human‐environment interactions. The goal is to generate compatible data sets that extend across social, biophysical, and geographical domains so that the causes and consequences of land use and land cover dynamics might be explored within a spatially‐explicit context. 相似文献
16.
《测量评论》2013,45(84):268-274
AbstractIn the E.S.R., viii, 59, 191–194 (January 1946), J.H. Cole gives a very simple formula for finding the length of long lines on the spheroid (normal section arcs), given the coordinates of the end points. In the course of the computation the approximate azimuth of one end of the line is found, the error over a 500-mile line being of the order of 3″ or 4″. If the formula is amended so that the azimuth at the other end of the line is used in computing the length of the arc, the error is then less than 0″·1 over such a distance. An extra term is now given which makes this azimuth virtually correct over any distance. Numerical tests show that Cole's formula for length and the new one for azimuth are very accurate and convenient in all azimuths and latitudes. 相似文献
17.
《测量评论》2013,45(73):119-130
Abstract1. This new method of adjusting air photographs numerically to a uniform scale on a final map grid has already been described by the writert, where it concerns a large block-adjustment. The method to be described in this paper is the application of the same principle to the adjustment of photographic strips, covering narrow land areas and coastlines. 相似文献
18.
《测量评论》2013,45(39)
AbstractThe most northerly point of any tract of land is that point which is nearest to the north pole; and the most westerly point is that which has the greatest westerly longitude, or the least easterly longitude. But is there a most north-westerly point? Or is north-west, in this connection, only a relative term, depending upon the position of some other point? 相似文献
19.
Galina Churkina Kristina Trusilova Mona Vetter Frank Dentener 《Carbon balance and management》2007,2(1):5-7
Background
The amount of reactive nitrogen deposited on land has doubled globally and become at least five-times higher in Europe, Eastern United States, and South East Asia since 1860 mostly because of increases in fertilizer production and fossil fuel burning. Because vegetation growth in the Northern Hemisphere is typically nitrogen-limited, increased nitrogen deposition could have an attenuating effect on rising atmospheric CO2 by stimulating the vegetation productivity and accumulation of carbon in biomass. 相似文献20.
《测量评论》2013,45(19):258-266
AbstractThe following account of the standardizing equipment of the Gold Coast Survey Department has been written, at the request of the Editor of the Review, because this equipment includes a completely enclosed standard of length 300 feet long which is believed to be one of the very few enclosed standards of this length in any of the Crown Colonies. 相似文献