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本文基于对传统不变目标区域校正法的改进,选择4期辐射定标参考影像对DMSP-OLS影像进行了饱和校正与时间序列连续性校正。通过阈值法去除了NPP-VIIRS影像的背景噪声及异常值,利用对数变换压缩了其灯光辐射值的动态范围,使其亮度分布更接近于DMSP-OLS数据。利用BiDoseResp函数模型对NPP-VIIRS影像进行了一致性校正,获得了1992-2019年长时间序列夜间灯光影像。从定性、定量及校正影像与社会经济参量的相关性方面对校正结果进行了精度验证。结果表明,改进后的校正方法改善了DMSP-OLS影像饱和严重的现象,使其获得了长时间序列纵向可比性。BiDoseResp函数模型可以很好地拟合DMSP-OLS和对数变换后的NPP-VIIRS之间的回归。校正后的长时间序列灯光影像数据与社会经济参量高度契合。校正结果对推广长时间序列夜间灯光影像的广泛应用、深化长时间序列科学问题的研究具有重要价值。 相似文献
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DMSP-OLS夜间灯光遥感数据截至2013年,现已被NPP-VIIRS夜间灯光数据取代。因此,要获得长时间序列且稳定的夜间灯光数据集,需要整合两类夜间灯光数据。基于此,本文提出了基于重采样的两类数据整合方法,对2013—2020年NPP-VIIRS数据进行模拟,最终建立了1992—2020年长时间序列校正—模拟DMSP-OLS夜光遥感数据集。结果表明,基于重采样的整合方法效果良好(城市区域Pearson相关系数ρ=0.9852,RMSE=3.4607),整合数据集与相关社会经济参考量高度契合(影像DN值总和与GDP的相关系数ρ=0.946,与人口的相关系数ρ=0.971,二次多项式模型拟合R2≈0.98,RMSE<5.55),优于已有研究。因此,利用该方法整合后的数据集能更好地支撑基于夜间灯光影像的长时间序列研究。 相似文献
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The defense meteorological satellite program (DMSP) operational linescan system (OLS) sensors have imaged emitted light from Earth's surface since the 1970s. Temporal overlap in the missions of 5 OLS sensors allows for intercalibration of the annual composites over the past 19 years (Elvidge et al., 2009). The resulting image time series captures a spatiotemporal signature of the growth and evolution of lighted human settlements and development. We use empirical orthogonal function (EOF) analysis and the temporal feature space to characterize and quantify patterns of temporal change in stable night light brightness and spatial extent since 1992. Temporal EOF analysis provides a statistical basis for representing spatially abundant temporal patterns in the image time series as uncorrelated vectors of brightness as a function of time from 1992 to 2009. The variance partition of the eigenvalue spectrum combined with temporal structure of the EOFs and spatial structure of the PCs provides a basis for distinguishing between deterministic multi-year trends and stochastic year-to-year variance. The low order EOFs and principal components (PC) space together discriminate both earlier (1990s) and later (2000s) increases and decreases in brightness. Inverse transformation of these low order dimensions reduces stochastic variance sufficiently so that tri-temporal composites depict potentially deterministic decadal trends. The most pronounced changes occur in Asia. At critical brightness threshold we find an 18% increase in the number of spatially distinct lights and an 80% increase in lighted area in southern and eastern Asia between 1992 and 2009. During this time both China and India experienced a ∼20% increase in number of lights and a ∼270% increase in lighted area – although the timing of the increase is later in China than in India. Throughout Asia a variety of different patterns of brightness increase are apparent in tri-temporal brightness composites – as well as some conspicuous areas of apparently decreasing background luminance and, in many places, intermittent light suggesting development of infrastructure rather than persistently lighted development. Vicarious validation using higher resolution Landsat imagery verifies multiple phases of urban growth in several cities as well as the consistent presence of low DN (<∼15) background luminance for many agricultural areas. Lights also allow us to quantify changes in the size distribution and connectedness of different intensities of development. Over a wide range of brightnesses, the size distributions of spatially contiguous lighted area are consistent with power laws with exponents near −1 as predicted by Zipf's Law for cities. However, the larger lighted segments are much larger than individual cities; they correspond to vast spatial networks of contiguous development (Small et al., 2011). 相似文献
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1992-2010年基于DMSP-OLS图像的环渤海城市群空间格局变化分析 总被引：2，自引：0，他引：2
从DMSP-OLS数据提取城市区域的经验阈值法存在固有的缺陷,经验阈值对不同的空间区域不具备通用性,不适用的经验阈值,将导致城区面积提取具有较大误差,可采用统计数据对经验阈值进行修正以降低误差。本文在大时空尺度条件下以少量样本城市的统计数据对经验阈值方法进行了修正;另采用Elvidge二次多项式模型对DMSP-OLS时间序列数据进行了校正。在此基础上选取总斑块数量、景观总面积、平均斑块大小、最大斑块面积比、斑块密度、景观形状指数、总边界长度、平均边界密度和斑块平均回旋半径共9个景观生态学指标,采用FRAGSTATS 3.3软件计算分析了1992-2010年环渤海区域城市发展的空间格局变化特征。结果表明:1992-2010年间,环渤海区域城市化进程持续较快发展,城市建成区总面积增加了2.14倍,平均城市建成区面积增加了76%,提取到的城市斑块平均回旋半径增加了约26.5%,并且城市景观斑块的复杂度明显上升,可检测到的城镇总个数增加了82%。但是,每100km2内孤立的城市景观斑块数却降低了约76%;大城市持续扩张的相对速度慢于中小城市,城市区域边界密度和整体城市分布景观格局破碎度逐渐降低,核心城市与周围卫星城市的景观斑块的联通性逐步增加。 相似文献
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Object-based spatial cluster analysis of urban landscape pattern using nighttime light satellite images: a case study of China 总被引：1，自引：0，他引：1
Bailang Yu Song Shu Hongxing Liu Wei Song Jianping Wu Lei Wang 《International journal of geographical information science》2014,28(11):2328-2355
Previous studies have demonstrated urban built-up areas can be derived from nighttime light satellite (DMSP-OLS) images at the national or continent scale. This paper presents a novel object-based method for detecting and characterizing urban spatial clusters from nighttime light satellite images automatically. First, urban built-up areas, derived from the regionally adaptive thresholding of DMSP-OLS nighttime light data, are represented as discrete urban objects. These urban objects are treated as basic spatial units and quantified in terms of geometric and shape attributes and their spatial relationships. Next, a spatial cluster analysis is applied to these basic urban objects to form a higher level of spatial units – urban spatial clusters. The Minimum Spanning Tree (MST) is used to represent spatial proximity relationships among urban objects. An algorithm based on competing propagation of objects is proposed to construct the MST of urban objects. Unlike previous studies, the distance between urban objects (i.e., the boundaries of urban built-up areas) is adopted to quantify the edge weight in MST. A Gestalt Theory-based method is employed to partition the MST of urban objects into urban spatial clusters. The derived urban spatial clusters are geographically delineated through mathematical morphology operation and construction of minimum convex hull. A series of landscape ecologic and statistical attributes are defined and calculated to characterize these clusters. Our method has been successfully applied to the analysis of urban landscape of China at the national level, and a series of urban clusters have been delimited and quantified. 相似文献
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Dark Times: nighttime satellite imagery as a detector of regional disparity and the geography of conflict 总被引：1，自引：0，他引：1
Luca Coscieme Paul C. Sutton Sharolyn Anderson Qing Liu Christopher D. Elvidge 《地理信息系统科学与遥感》2017,54(1):118-139
Satellite observations of night-time emitted lights describe a geography of the spatial distribution of resource use. Measurements of nocturnal lights enable the calculation of the total light emitted from each country of the world, and the light emitted per capita. We consider different groups of countries that share a land or maritime border and whose light per capita can be more equally/unequally distributed. A sharp difference in light per capita among neighboring countries reflects marked differences in economic welfare and in the extent of built environments. We demonstrate how this geography of nocturnal lights informs our understanding of the dynamics of conflict at the national and regional scale. We propose an index of regional disparity and test its ability to detect conflict dynamics by relating the index score with the occurrence and intensity of conflicts as classified by the Heidelberg Institute for International Conflict Research’s Conflict Barometer 2012 for the countries of the world. This method can be used to produce a global available temporal sampling of “cold spots” of disparity where conflicts are likely to occur. This will help foresee the identification and monitoring of regions of the world,which are becoming particularly unstable, assisting in the definition and execution of timely and proactive policies. 相似文献
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中国低碳城市评价与空间格局分析 总被引：1，自引：1，他引：0
城市是人类生产和消费活动最为集中的区域,带来了大量的能源消耗和碳排放,低碳城市受到国内外学者广泛探讨。本文从低碳开发、低碳经济、低碳环境、城市规模与能源消耗5个方面22个指标构建了低碳城市评价体系,引入遥感影像中的DMSP-OLS夜间灯光数据集与PM2.5浓度反演影像;利用因子分析、聚类分析及空间相关性分析,将2006年及2010年284个地级及以上城市按照低碳水平分为低碳、相对低碳、相对高碳、高碳四类城市;根据驱动力分为环境主导型、居民主导型、城镇化主导型及产业主导型四种城市类型;空间上识别出京津冀、长三角、山东省及珠三角地区具有低碳城市发展集聚效应;低碳城市发展水平受城市行政等级、产业转型等因素影响。 相似文献
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Electricity is one of the most important components in energy consumption, which is directly related to economic growth, CO2 emission and global warming. This research intends to estimate spatial distribution of electricity consumption in China, the largest developing country, and analyze the temporal and spatial change of electricity consumption during 1994–2009. The spatial modeling is based on the total electricity consumption of each province and DMSP (Defense Meteorological Satellite Program) – Operational Line-scan System (OLS) data, the latter provides the nighttime light information corresponding to electricity consumption, GDP and population. A simple method was developed to correct the saturated pixels with digital number of 63 in non-radiance-corrected DMSP-OLS data, using cities’ GDP data. The spatial electricity consumption maps were produced during 1994–2009, and they were validated by the electricity consumption records of 101 cities. Finally, the spatial–temporal changes of electricity consumption were analyzed. The results of this research can help to understand the regional discrepancy, especially rural and urban areas of China, of electricity consumption and economic development. 相似文献
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夜间灯光数据记录了地球表面的人造灯光强度,是估计社会统计指标的有效手段之一。为了评估DMSP-OLS和NPP-VIIRS 2种夜间灯光数据对社会统计指标的模拟潜力,采用4种常用的灯光校正方法分别对2种夜间灯光数据进行灯光饱和性校正,根据校正后的夜间灯光数据分别建立与京津冀地区县域GDP、人口和能源消耗3种社会统计指标间的线性回归模型,从模型拟合的相关系数、F统计量值与概率p值中分析并评价了2种夜间灯光数据对GDP、人口和能源消耗3种社会统计指标的测算能力。本文研究结果表明：EANTLI法是2种夜间灯光数据的最佳校正方式,而HSI法不适用于夜间灯光数据校正后与县域社会统计指标的线性关系拟合2种夜间灯光数据对GDP的拟合效果都较好,NPP-VIIRS夜间灯光数据估算社会统计指标的拟合能力要优于DMSP-OLS数据。 相似文献
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