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最短路径问题是地理网络分析中的重要问题之一，具有重要的应用价值。搜索最短路径的方法很多，在研究了各种方法后，本文提出了在ArcGIS矢量图中搜索最短路径的新方法。首先，提取经过ArcGIS简单处理的矢量图的信息，然后，借助Floyd算法，用MATLAB建模来提取节点间的最短路径，最后根据模型运算的结果在矢量图中绘出最短路径。试验证明，该方法操作简单，效果良好。 相似文献
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最短路径算法:分类体系与研究进展 总被引：76，自引：3，他引：76
最短路径算法是计算机科学与地理信息科学等领域的研究热点。本文首先讨论了平面图的搜索策略，然后从问题类型、网络类型和实现方法3方面对最短路径算法进行了系统的分类，从理论上比较了近年来所提出的各具有较高效率的串行最短路径算法的时间复杂度，并对国内外一些相关研究进行了综合评述，结合城市交通网络的实验结果，作者对几种应用最为广泛的串行最短路径算法的运行效率进行了分析和评价，最后对最短路径算法在实时化和并行化方面的发展进行了讨论。 相似文献
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一、前言应国家测绘局测绘标准化研究所“关于进行标准化专题研究委托协议书”的要求，我们完成了有关“特高精度水准测量方法”的研究项目。此专题研究之目的在于，在采用当前最先进的设备和最严密的方法的前提下，探讨最高精度的高程传递的具体方法，为精密工程测量规范中确定高程测量方法和精度指标提供依据。 相似文献
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在中国控制SARS(Severe Acute Respiratory Syndrome)疫情扩散与蔓延的大量科学实践活动基础上，从人地系统科学的理论和观点出发，提出了各种致病因子在人地互动过程中转移路径的逻辑模型，进而又提出了控制SARS疫情发展的人地互动逻辑模型。从后一个模型出发，把中国SARS疫情的发展规律归纳为5种传播模式，即异类病毒转移传播模式、家庭和社区接触传播模式、医院和门诊感染传播模式、市内随机扩散传播模式和飞点跳跃跨区传播模式。其中，跨区传播模式的影响最广泛、危害最巨大、控制起来最艰巨、复 相似文献
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最短路径算法是GIS空间分析研究的热点问题。本文将最短路径的实时计算转换为预计算，利用关系数据库将最短路径计算过程和结果实例化，并在WebGIS环境下实现了城市任意两点之间最短路径的快速计算和响应。 相似文献
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系统地介绍了土地利用管理系统的开发设计方案。该系统在参考目前最先进的技术方法的基础上，采用最实用的结构设计，以便解决土地利用管理方面的各种应用问题。 相似文献
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1943～1944年是抗日战争最危急、最紧张的时刻。日本侵略军攻陷了缅甸仰光,从利多、密支那长驱直入龙陵,占领松山,威胁保山及昆明。日寇叫嚣要在三个月内攻占重庆，我国援缅远征军不得不炸掉惠通桥。史迪威公路被切断后，中国几乎成了瓮中之鳖，盟军不得已启动驼峰计划，陈纳德将军的飞虎队飞越驼峰押送援华物资。 相似文献
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C. J. Thampi 《Journal of the Indian Society of Remote Sensing》1983,11(1):23-29
The paper discusses the use of Remote Sensing techniques for the integrated economic land use planning in Andaman and Nicobar Islands, agricultural land use being the main objective. Broad aspects of physiography, soil, land use etc. have been described. An idea about the soil environment and erosion hazards is given. A land use pattern on the basis of land capability and land suitability classification together with cropping pattern has been evolved and the model has been developed for the Island. 相似文献
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P. V. Arun 《Journal of the Indian Society of Remote Sensing》2014,42(1):217-226
Entropy is the measure of uncertainty in any data and is adopted for maximisation of mutual information in many remote sensing operations. The availability of wide entropy variations motivated us for an investigation over the suitability preference of these versions to specific operations. The popular available versions like Tsalli’s, Shannon’s, and Renyi’s entropies have been analysed in context of various remote sensing operations namely thresholding, clustering and registration. These methodologies have been evaluated with reference to the study area using different statistical parameters. Renyi’s entropy has been found to be suitable for image registration purpose followed by Tsalli’s and Shannon; whereas Tsalli’s entropy has been found preferable for thresholding and clustering. 相似文献
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In recent years hyperspectral imaging has proved its significance in the detection and mapping of various objects of interest in a scene. Various methods for object detection in hyperspectral images have been developed with their advantages and limitations. In the present study, a methodology comprising spectral derivative (first order) and spectral information divergence has been investigated for detection of objects in hyperspectral images. The efficacy of the detection scheme has been examined over two different hyperspectral data sets of Hyperion images. Tea plants (Camellia sinensis) and Sal trees (Shorea robusta) (pure pixels) have been detected as the objects of interest in the hyperspectral images independently with reduced false pixels. The proposed methodology may in future be applied for classification of mixed pixels. 相似文献
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Abstract Change detection study has been made for the mangrove forest of the Sunderbans (Bangladesh) using remote sensing and other ancillary data (1933–1987). At the advent of the British rule the forest was double their present extent. Its present area is about 6000.0 Sq. Km. The productive land area has been increased from 1960. Gewa (Excoecaria agallocha)‐Sundri (Heritiera fames) cover type areas have been increased at the expense of pure Sundri type. Height classes of the forest have been changed, basal area/ha has decreased. It is observed that there is a net decrease in Sundri standing volume of the order of 40% and that of Gewa 45% over the past 25 years (1960–1985). Total timber volume for all of the species has been reduced to near about a half. Timber volume/ha and basal area/ha for Gewa have increased in the Sharankhola Island of the forest. Sundri tress are being replaced by Gewa. CIR aerial photographs have been found most suitable for cover type analysis and other change detection study. Regular monitoring of the changes of the forest using remote sensing technique has been suggested. 相似文献
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Grand Erg Oriental of the Algerian Sahara is one of the most difficult terrain having high altitude dunes ranging in height from 100 m to 300 m above ground level and 250 m to 530m above M.S.L. Interpretation of space Imagery for morphotectonic features like structures and lineaments over such a rough terrain had been an enigma. For the first time in 1978 an attempt was made in connection with exploration for hydrocarbons. A new approach on the hypothesis that the configuration of dunes is directly related to the subsurface topography which in turn being the product of geology and tectonics has been developed and the results obtained had been encouraging. The study resulted in delineating of more than 200 structures and 700 lineaments. Many of these have since been confirmed by geophysical survey and subsequent drilling. It is observed that the deep seated structures are more prone to interpretation on Landsat frames, in areas covered by high dunes as compared to lineaments. Contact of dune types, identified, may reflect variation in subsurface geology. 相似文献
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K. K. Singh V. D. Mishra Sahil Sood Manoj Kumar 《Journal of the Indian Society of Remote Sensing》2013,41(4):947-956
The present study aims to estimate the long term changes in sea ice areal extent (SIAE) around Antarctica using Special Sensor Microwave Imager (SSM/I) satellite data (1988–2011). Daily, weekly and monthly brightness temperature (TB) maps of Antarctica have been generated. Temporal variation in monthly averaged TB values of sea ice have been analyzed and an increasing trend is observed in TB. Sea ice concentration (SIC) values are estimated and the concentration class 0.85–0.95 is observed as the main contributor in sea ice areal extent during the Antarctic peak winter month i.e. September and October. SIC changes rapidly from October onwards and shows fast melting of sea ice, however, from April start of freezing has been observed. Continuous increase in SIAE is observed from February to September in all the analyzed years (1988–2011) data. In this observation period maximum SIAE is observed in September 1989 and minimum in February 1993. The Moderate Resolution Imaging Spectroradiometer (MODIS) data is used for the validation of SIAE values. SSM/I and MODIS estimated SIAE values are compared (R2?=?0.98) and a relation between them is established by performing regression analysis. This relation is further used for the estimation of corrected SIAE values. The monthly average sea ice extent maps of last three decades have been analyzed and a shift in onset of freezing of sea ice has been observed. The period of frozen sea has also been observed as decreased. 相似文献
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文章运用实测数据和数理统计有关理论,对实验区的第二次土地调查成果进行实测验证,并通过计算和比较分析,得出客观的结果,为以后二调成果的应用提供了相应的依据。 相似文献
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This paper is based on a case study of Delhi. The attempt has been made to find out the usefulness of aerial remote sensing in the study of urban fringe where all sorts of haphazard developments take place. Unauthorised construction, illegal sub-division of land, urban sprawl, environmental degradation are all parts of urban fringe Attempt has been made to find out the efficacy of aerial photos at pre-planning stage and their role in assigning various landuses for planned development of urban fringe zone. For the first time, the concept of “Urban Index” has been used to determine the scale of urbanity by aerial remote sensing technique. Growth of settlements, land speculation, impact of anticipated development proposal have been studied. Aerial photographs have been used to detect depressions, drainage pattern, flooding problems, location of high ground water table areas which are very important for a comprehensive planning and for environmental protection. Limitations of topomaps compared to aerial photographs have been worked out. The study is based on air photo-interpretation technique supported by field checking. *** DIRECT SUPPORT *** A04KF011 00003 相似文献