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1.
Joaquim Alves Gaspar 《The Cartographic journal》2013,50(4):318-324
In this paper, the results of a cartometric analysis of a number of Portuguese and Spanish charts of the sixteenth and seventeenth centuries are presented and conclusions are drawn concerning the length of the degree of latitude adopted in the Iberian nautical cartography of the Renaissance. Under the light of what we know about the navigational and charting methods of the time, a new interpretation of the textual and cartographic sources is proposed. Rather than being the result of technical considerations or precise measurements, the adoption of the various standards during this long period appears to be no more than the echoes of the traditional models of the Earth and of the political disputes between Portugal and Spain. 相似文献
2.
SONG Qiurong SONG Qiurong Ph.D candidate the Institute of Higher Education Huazhong University of Science Technology Wuhan China. 《地球空间信息科学学报》2002,5(3):65-70
One of the most impor tant factors impacting the development of today‘s private higher education in China is that there are not enough policies to support in.Then,the history of private higher educationin Nanjing Nationalist Government(1927-1749)is focused on. 相似文献
3.
Takashi Morita 《制图学和地理信息科学》2013,40(2):140-151
ABSTRACTBertin’s first book, Semiology of Graphics, was published in 1967. His second book, Graphics and Graphic Information Processing, was subsequently published in 1977. The word “processing” in the title of the second book is interesting because in those days there were no personal computers with an interactive display system. But in Bertin’s laboratory there were many kinds of tool kits – basically manually developed thematic maps and data analysis. Bertin’s methods were concerned with making a thematic map and data visualization. Maps, and more generally graphics, were represented by sets of cartographic symbols. Thus, they are abstractions that demand both theoretical and technical literacy to represent and understand them. If the representation is systematic, a sort of tool kit might be necessary, because the representation demands consistency based on the theory. Otherwise a cartographer faces the risk of an unstable and unintelligible representation. In this paper, we discuss the discrimination between tool kits intended either for an automated system or a process assisting system. The latter process might be useful and necessary to develop a graphic way of thinking. This investigation refers to Bertin’s books, materials conserved at the National Archives in Paris, and other related software developed later.Abbreviation: EHESS: Ecole des Hautes Etudes en Sciences Sociales inherited Ecole Pratique des Hautes Etudes since 1975 相似文献
4.
DanteSalvini 《地球空间信息科学学报》2002,5(1):18-21
One type of aerial cableway consists of a continuous cable,which works at the same time as carrying cable and drawing cable.This kind of cableway is supported by many towers,which divide the total length in linear sections.even small deviations from the planed layout can increase the strain of the cable and the danger of derailments.The deviations of the position of the towers from the planed layout are due to local sliding or sinking of the foundation or other mechanical movements.Up to now the axis of the cableways were periodically measured by traditional methods. The goal of this project is to demonstrate the possibility of measuring the axis of a cableway with GPS techniques,while the cable is moving.The results show that the proposed measuring device provides precise results in a simple and reliable way. 相似文献
5.
《制图学和地理信息科学》2013,40(3):154-169
In an historically contextualized overview of the earliest extant version of the Yujitu, engraved on stone under the Liu Yu regime but believed to be a copy of a Northern Song map, the paper analyzes factors that complicate its georeferencing. The paper introduces a new algorithm for nonlinear georeferencing, applying it to 45 points and finding that the placement of sites on the north-south axis must have been based on latitudinal observation. Despite the Yujitu's startlingly modern appearance, the paper finds that there are areas in which it reflects a loyalty to classical texts. 相似文献
6.
7.
XU Xiaohua LI Zhenghang LUO Jia 《地球空间信息科学学报》2006,9(1):13-17
Introduction WithGPSreceiversmountedonLEOsatel lites,GPSoccultationeventscanbeobserved.Theobservablesarevaluableforatmospheric monitoringandweatherforecasting.Whenpre paringtobuildupanLEOsatelliteoccultation observationsystem,theevaluation,designand imple… 相似文献
8.
Joel Radunzel 《制图学和地理信息科学》2013,40(6):502-517
ABSTRACTDuring Palestine Campaign of World War I, the British Army’s Egyptian Expeditionary Force produced a series of operation maps to track and control the progress of their offensive into Palestine. These maps demonstrated innovation in both their form and function, and they have been referenced and reproduced by both map scholars and military historians ever since. Leaning on J.B. Harley and Matthew Edney’s ideas about critical map history, this essay provides a critical examination of these operation maps to illuminate the sociocultural context of their creation and examines the maps’ influence over the broader historiography of the Palestine Campaign. In doing so it highlights the interdisciplinary value of critical map histories. 相似文献
9.
The second-order derivatives of the Earth’s potential in the local north-oriented reference frame are expanded in series of
modified spherical harmonics. Linear relations are derived between the spectral coefficients of these series and the spectrum
of the geopotential. On the basis of these relations, recurrence procedures are developed for evaluating the geopotential
coefficients from the spectrum of each derivative and, inversely, for simulating the latter from a known geopotential model.
Very simple structure of the derived expressions for the derivatives is convenient for estimating the geopotential coefficients
by the least-squares procedure, at a certain step of processing satellite gradiometry data. Due to the orthogonality of the
new series, the quadrature formula approach can be also applied, which allows avoidance of aliasing errors caused by the series
truncation. The spectral coefficients of the derivatives are evaluated on the basis of the derived relations from the geopotential
models EGM96 and EIGEN-CG01C at a mean orbital sphere of the GOCE satellite. Various characteristics of the spectra are studied
corresponding to the EGM96 model.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
10.
Tondozi Keto LIU Tianyou 《地球空间信息科学学报》2005,8(4):291-296
IntroductionGeophysics as its nameindicates has to do withthe physics of the earth and its surrounding at-mosphere . Gilbert’s discovery that the earth be-haves as a great and rather irregular magnet andNewton’s theory of gravitation may be said toconstitute the beginning of geophysics . Miningand the search of metals date from the earliestti mes , but the scientific record began with thepublicationin 1956 of the famous treatise De remetallica by Georgius Agricola , whichfor manyyears was … 相似文献
11.
The multispectral and multitemporal analysis of the spectral response of rice has made it possible to determine at which point in the vegetative cycle of rice it is best to make an inventory, together with the usefulness of the normalized‐difference vegetation index for such an inventory. The results could be usefully included in any classification procedure of the TM image in order to make the inventory in a systematic way. In this case a supervised classification of the image has been made which assumes a Gaussian behaviour for each spectral class. The results obtained are, for the most part, consistent with those obtained by using traditional methods. 相似文献
13.
A growing number of studies have focused on variations in vegetation phenology and their correlations with climatic factors. However, there has been little research on changes in spatial heterogeneity with respect to the end of the growing season (EGS) and on responses to climate change for alpine vegetation on the Qinghai–Tibetan Plateau (QTP). In this study, the satellite-derived normalized difference vegetation index (NDVI) and the meteorological record from 1982 to 2012 were used to characterize the spatial pattern of variations in the EGS and their relationship to temperature and precipitation on the QTP. Over the entire study period, the EGS displayed no statistically significant trend; however, there was a strong spatial heterogeneity throughout the plateau. Those areas showing a delaying trend in the EGS were mainly distributed in the eastern part of the plateau, whereas those showing an advancing trend were mostly scattered throughout the western part. Our results also showed that change in the vegetation EGS was more closely correlated with air temperature than with precipitation. Nonetheless, the temperature sensitivity of the vegetation EGS became lower as aridity increased, suggesting that precipitation is an important regulator of the response of the vegetation EGS to climate warming. These results indicate spatial differences in key environmental influences on the vegetation EGS that must be taken into account in current phenological models, which are largely driven by temperature. 相似文献
14.
YAO Yibin 《地球空间信息科学学报》2007,10(4):240-244
With the daily SINEX files of the IGS, the time series of IGS stations are obtained using an independently developed software under generalized network adjustment models with coordinate patterns. From ... 相似文献
15.
《International Journal of Digital Earth》2013,6(3):284-306
ABSTRACTOpen data are currently a hot topic and are associated with realising ambitions such as a more transparent and efficient government, solving societal problems, and increasing economic value. To describe and monitor the state of open data in countries and organisations, several open data assessment frameworks were developed. Despite high scores in these assessment frameworks, the actual (re)use of open government data (OGD) fails to live up to its expectations. Our review of existing open data assessment frameworks reveals that these only cover parts of the open data ecosystem. We have developed a framework, which assesses open data supply, open data governance, and open data user characteristics holistically. This holistic open data framework assesses the maturity of the open data ecosystem and proves to be a useful tool to indicate which aspects of the open data ecosystem are successful and which aspects require attention. Our initial assessment in the Netherlands indicates that the traditional geographical data perform significantly better than non-geographical data, such as healthcare data. Therefore, open geographical data policies in the Netherlands may provide useful cues for other OGD strategies. 相似文献
16.
P. Vaníček J. Huang P. Novák S. Pagiatakis M. Véronneau Z. Martinec W. E. Featherstone 《Journal of Geodesy》1999,73(4):180-192
The definition of the mean Helmert anomaly is reviewed and the theoretically correct procedure for computing this quantity
on the Earth's surface and on the Helmert co-geoid is suggested. This includes a discussion of the role of the direct topographical
and atmospherical effects, primary and secondary indirect topographical and atmospherical effects, ellipsoidal corrections
to the gravity anomaly, its downward continuation and other effects. For the rigorous derivations it was found necessary to
treat the gravity anomaly systematically as a point function, defined by means of the fundamental gravimetric equation. It
is this treatment that allows one to formulate the corrections necessary for computing the `one-centimetre geoid'. Compared
to the standard treatment, it is shown that a `correction for the quasigeoid-to-geoid separation', amounting to about 3 cm
for our area of interest, has to be considered. It is also shown that the `secondary indirect effect' has to be evaluated
at the topography rather than at the geoid level. This results in another difference of the order of several centimetres in
the area of interest. An approach is then proposed for determining the mean Helmert anomalies from gravity data observed on
the Earth's surface. This approach is based on the widely-held belief that complete Bouguer anomalies are generally fairly
smooth and thus particularly useful for interpolation, approximation and averaging. Numerical results from the Canadian Rocky
Mountains for all the corrections as well as the downward continuation are shown.
Received: 9 March 1998 / Accepted: 16 November 1998 相似文献
17.
Sebastian Orihuela 《The Cartographic journal》2013,50(2):158-165
The Lagrange projection represents conformally the terrestrial globe within a circle. This is achieved by compressing the latitude and longitude and by applying the new coordinates into the equatorial stereographic projection. The same concept can be generalized to any conformal projection, although the application of this technique to other analytical functions is less known. In this work, the general Lambert–Lagrange projection formula is proposed and the application of the modified coordinates is discussed on projections: stereographic, conformal conic and Gauss–Schreiber. In general, the results are merely a curiosity, except for the case of Gauss–Schreiber, where the use of coordinates with altered scale can be applied in the optimization of conformal projections. 相似文献
18.
《测绘学报》2012,41(3)
利用轨道扰动引力谱和大地水准面累计误差谱分析的方法估计未来GRACE（gravity recovery and climate experimenl）Follow—On卫星反演地球重力场的空间分辨率。基于GRACEFollow—On卫星的轨道特性,计算其在高空所受到的径向扰动引力,并根据谱特性及星载加速度计的测量噪声水平分析该卫星能反演重力场的阶数。利用EGM96重力场模型分别计算200km和250km轨道高度处的扰动引力谱。分析其特性表明：在两个轨道高度处分别能反演281阶和242阶的地球重力场模型。给出大地水准面累计误差谱模型,并计算200km和250km轨道高度处大地水准面累计误差谱。分析其谱特性表明：在两个轨道高度处分别能反演至286阶和228阶的地球重力场模型。 相似文献
19.
WANG Yong LIU Yanping LIU Lintao XU Houze 《地球空间信息科学学报》2007,10(4):265-268
The feasibility of GPS precipitable water vapor (PWV) is discussed based on the comparison of Radiosonde and GPS PWV where the correlation coefficient is 0.94 and the RMS is 4.0 mm. PWV change in the C... 相似文献
20.
As a result of the 1991 Persian Gulf war, between mid‐January and June 1991, the Persian Gulf was contaminated with an estimated 4 to 6 million barrels of crude oil, released directly into the Gulf from refinement facilities, transhipment terminals, and moored tankers along the coast of Kuwait, and precipitated from oil fire smoke plumes. To assess the environmental impact of the oil, an international team of marine scientists representing 14 nations was assembled under the auspices of the United Nations International Oceanic Commission and the Regional Organization for Protection of the Marine Environment to conduct detailed surveys of the Persian Gulf, the Strait of Hormuz, and the Gulf of Oman, including hydrographic, chemical, and biological measurements. To supplement the field surveys and to serve as an aid in data interpretation, astronauts aboard the Space Shuttle Atlantis photographed water features and coastal habitats in the Persian Gulf during mission STS‐45 (24 March to 02 April 1992). The astronauts collected 111 hand‐held, color photographs of the Gulf (72 70 mm photographs and 39 5‐inch photographs) from an altitude of 296 km (160 n.mi.). The photographs reveal distributions in water turbidity associated with outflow from the Shatt‐al‐Arab and water circulation along the entire coast of Iran and the Strait of Hormuz, coastal wetlands and shallow‐water habitats, and sticks appearing in the sunglint pattern, which appear to be oil. 相似文献