共查询到18条相似文献,搜索用时 56 毫秒
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DMSP/OLS夜间灯光数据是提取大尺度城镇用地信息的有效数据手段。利用DMSP/OLS稳定夜间灯光数据,在传统二分比较法的基础上,发展一种提取城镇用地信息的新方法——分层阈值法。该方法采用分层分类的思想,不断地将灯光阈值相近的行政单元划分到相同的集合,直至集合内各行政单元的灯光阈值完全相同为止。基于分层阈值法,从2002年DMSP/OLS稳定夜间灯光数据中提取中国内地的城镇用地信息,并利用统计数据和Landsat ETM+数据分别从数量特征和空间格局上对提取结果进行精度评价。研究结果表明,分层阈值法不仅克服了传统二分比较法需要逐个行政单元求取阈值导致计算效率较低的缺陷,优化了阈值求解过程,提高了城镇用地信息提取效率,而且具有较高的可靠性和推广应用价值。 相似文献
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绍兴市城镇聚落空间形态信息提取及其演化的分形分析 总被引:3,自引:1,他引:2
通过对绍兴市1984年8月和1997年5月两景不同时相的TM遥感影像上城镇及其背景地物的光谱特征分析,建立城镇聚落信息提取的光谱模型,提取城镇聚落形态信息,利用中值滤波进行整体化处理,后再矢量化。在此基础上,利用分形几何理论计算不同时相、不同组合的绍兴市城镇聚落形态的分形维数,对比分析其空间形态的变化特征。结果表明,绍兴市城镇聚落的空间形态明显具有分形特征,而且形态越来越复杂,稳定性越来越低,发展越来越随意。其中,绍兴市区和柯桥镇的发展尤为迅速,与其它集镇相比,其空间形态的复杂程度更高,稳定性更低,随意性更大。 相似文献
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针对三维测量中条纹图像序列的特点,对固定阈值、准自适应阈值和自适应阈值的二值化方法进行深入分析和对比研究,提出了利用图像差影实现时域二值化的算法.实验数据表明,时域二值化方法具有较好的抗干扰能力. 相似文献
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基于形态学的图像二值化方法 总被引:2,自引:0,他引:2
提出了一种自适应图像二值化方法,它基于数学形态学理论,求取彩色图像边缘特征,并将它与灰度直方图二值化方法相结合,实验表明,这一算法能较好地保留原图像中的特征,二值化后的图像效果不错。 相似文献
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基于TM影像的典型内陆淡水湿地水体提取研究 总被引:10,自引:1,他引:10
水是维系湿地生态系统稳定和健康的决定性因子,利用卫星遥感影像快速、准确地提取湿地水体信息已经成为湿地调查、研究与保护的重要手段。鉴于TM遥感影像具有较高的空间分辨率、波谱分辨率、极为丰富的信息量、较高的定位精度和相对较低的价格,其必然成为近一段时期湿地调查、研究与保护的重要数据源之一。研究基于TM遥感影像,运用多种方法针对典型内陆淡水湿地的水体信息进行了提取实验,通过对实验结果的分析得出:在面积的准确性、提取的准确度以及视觉效果3种指标下,光谱分类法较其它方法效果要好,其次为单波段阈值分析法与植被指数法,较差的是多波段谱间关系法与水体指数法;影响提取效果的主要原因是湿地水体提取不够完全,这是由影像的分辨率及湿地特殊的水文条件所造成的,采用像元分解及多源遥感数据融合技术将成为提高水体提取精度的重要手段。 相似文献
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The urban land cover structures play an important role in providing urban ecological service and altering the quality of human settlements environment.In this study,2000~2015 Landsat TM series satellite data along with fine resolution remote sensing images were used to capture information of each 5-year land cover structures in 12 prefecture-level cities of Inner Mongolia Autonomous Region.Subsequently,there land cover information was used to monitor and analyze the spatiotemporal dynamics of urban expansion,and differences of land cover structures and expansion types.The results showed that:in 2000~2015,the overall changes of land cover structures in 12 prefecture level cities of Inner Mongolia Autonomous Region were rapid.Specifically,the urban area expanded by 278.93 km2.By comparison,the proportion of urban area expansion in 2010~2015 was 1.61 times and 1.91 times than that of the first two periods (in 2000~2005 and in 2005~2010).Since 2010,the most dramatic changes has been observed.Particularly,obvious urban impervious surface expansion was found.Also urban vegetation showed obviously increased with varying degrees.At the past decade,urban expansion has undergone three stages.Specifically,the main process experienced from urban interior filling to urban interior filling and then to urban extension,of which Baotou and Hulunbeier belonging to the internal filling city.Population growth and socio-economic development are responsible for these differences. 相似文献
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基于QuickBird影像城市道路特征语义信息提取 总被引:1,自引:1,他引:0
快速、准确地获取城市道路信息,对于城市GIS数据更新具有重要意义。以昆明市为研究区,采用QuickBird卫星影像为数据源,开展了城市道路信息提取的特征语义信息提取实验研究。结果表明:①引入人脑认知OAR模型,提出高分辨率遥感影像城市道路认知框架,建立了道路信息提取语义模型,用数学方法和逻辑规则语言表达道路语义模型,再进行特征语义信息提取的研究思路是可行的;②采用Canny算子进行边缘检测道路、道路特征点细化、基于结点的线段追踪,进而提取对象语义信息、空间关系语义信息、局部上下文语义信息,最后通过GIS对提取的道路网络优化,实现道路网络最终提取,经检验提取道路信息长度的准确率为89.19%,宽度的准确率为71.54%,道路提取完整率为50.32%。 相似文献
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D. S. BOYD G. M. FOODY P. J. CURRAN R. M. LUCAS M. HONZAK 《International journal of remote sensing》2013,34(2):249-261
It has been postulated that tropical forests regenerating after deforestation constitute an unmeasured terrestrial sink of atmospheric carbon, and that the strength of this sink is a function of regeneration stage. Such regeneration stages can be characterized by biophysical properties, such as leaf and wood biomass, which influence the radiance emitted and/or reflected from the forest canopy. Remotely sensed data can therefore be used to estimate these biophysical properties and thereby determine the forest regenerative stage. Studies conducted on temperate forests have related biophysical properties successfully with red and near-infrared radiance, particularly within the Normalized Difference Vegetation Index (NDVI). However, only weak correlations have generally been observed for tropical forests and it is suggested here that the relationship between forest biophysical properties and middle and thermal infrared radiance may be stronger than that between those properties and visible and near-infrared radiance. An assessment of Landsat Thematic Mapper (TM) data revealed that radiance acquired in middle and thermal infrared wavebands contained significant information for the detection of regeneration stages in Amazonian tropical forests. It was demonstrated that tropical forest regeneration stages were most separable using middle infrared and thermal infrared wavebands and that the correlation with regeneration stage was stronger with middle infrared, thermal infrared or combinations of these wavebands than they were with visible, near infrared or combinations of these wavebands. For example, correlation coefficients increased from — 0·26 (insignificant at 95 per cent confidence level) when using the NDVI, to up to 0·93 (significant at 99 per cent confidence level) for a vegetation index containing data acquired in the middle and thermal infrared wavebands. These results point to the value of using data acquired in middle and thermal infrared wavebands for the study of tropical forests. 相似文献