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FY-3D极轨气象卫星作为最新一代的极地轨道气象卫星,其图像数据包含了丰富的植被、河流、山区等地表信息,对陆地资源调查、地表类型变化监测等具有重要作用。但几乎每轨遥感图像大约有2/3区域都被云雾覆盖,无法直接获取云层下的地表信息用于产品应用。本文研究晴空数据合成技术,首次提出反射率最小合成法、植被指数最大合成法和西格玛合成法的3个标准联合运用的晴空合成技术,利用先进的多时次气象卫星遥感数据合成技术,自动生成FY-3D中分辨率光谱成像仪(MERSI-II)250m分辨率晴空遥感数据,较好地实现了云和云阴影的去除,生成的晴空效果良好,具备了后续应用的价值。 相似文献
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利用遥感技术可快速、准确、大范围地监测矿山开发状况和了解矿区生态环境现状。以Landsat TM和CBERS卫星影像为主要数据来源,采用栅格数据、遥感数据与统计数据相结合的内业处理与外业调查相结合的技术路线,通过目视解译、人机交互解译、计算机自动识别等遥感信息提取技术和遥感影像处理,分析近20 a阜新市海州露天矿矿区面积变化趋势及近5a来对当地空气质量的影响。结果表明:阜新市海州露天矿矿区面积逐年减小,当地空气质量逐年优化。由此可见,露天矿矿区面积的减小对于当地空气质量的改善起到了一定的推动作用。 相似文献
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利用遥感技术可快速、准确、大范围地监测矿山开发状况和了解矿区生态环境现状。以Landsat TM和CBERS卫星影像为主要数据来源,采用栅格数据、遥感数据与统计数据相结合的内业处理与外业调查相结合的技术路线,通过目视解译、人机交互解译、计算机自动识别等遥感信息提取技术和遥感影像处理,分析近20 a阜新市海州露天矿矿区面积变化趋势及近5a来对当地空气质量的影响。结果表明：阜新市海州露天矿矿区面积逐年减小,当地空气质量逐年优化。由此可见,露天矿矿区面积的减小对于当地空气质量的改善起到了一定的推动作用。 相似文献
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基于决策树的郑州市土地利用与覆盖分类研究 总被引：2，自引：1，他引：1
以Landsat-7 ETM 1-7多波段遥感影像为数据源,采用决策树分类方法对郑州市土地利用及植被覆盖现状进行分类研究.在分析遥感影像波段载波信息量及野外样本选择、室内对比试验的基础上,制定节点上的分类规则,形成土地利用及植被覆盖色斑图,分类精度达到94%.结果表明:决策树方法优于传统的统计学分类方法,对数据并不要求正态分布,并且可以处理来自于遥感数据中的噪音和丢失数据.决策树分类法有诸如分类准确、高效,分类标准明确,分类结构直观、精度易于控制、分类自动化程度高等优势. 相似文献
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概述了水稻种植面积监测遥感数据源的应用变化、特征指数和时相选取以及遥感分类方法的发展,分析了MODIS影像在水稻种植面积遥感提取技术方面的研究进展及发展方向。结果表明：MODIS具有高光谱、高时间分辨率和多时相等特点,在大尺度上提取水稻种植面积上,可提高作物识别和监测的精确度与工作效率,节约成本,有着其他遥感数据无法相比的优势,应用MODIS数据提取水稻种植面积,取得了较好的效果。水稻遥感的最佳时相可以选择移栽期和孕穗期,利用对水体和植被较为敏感的波段或植被指数（如NDVI、LSWI和EVI）进行水稻识别,并提取种植面积。传统的遥感图像分类方法如监督分类和非监督分类,算法成熟、操作简单,是目前应用较多的方法。近年来发展起来的分类新方法,如决策树分类法、专家系统分类法、神经网络分类法,支持向量机法等,能够更准确地提取目标地物,对图像分类有不同程度的改进,在实际应用中通常和传统分类方法结合起来使用;多时相分析法与高时间、高分辨率多光谱影像的结合可以获取较高精度的作物种植面积数据,与传统分类方法相比有较大提高。利用MODIS对单一的或大面积的水稻种植面积提取效果较好,但对于地块破碎的种植面积估算尚难达到满意的结果,添加其他的辅佐数据如高程、坡度等,并结合MODIS数据的多时相特点分类等方法,可提高遥感影像分类的精度。 相似文献
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概述了水稻种植面积监测遥感数据源的应用变化、特征指数和时相选取以及遥感分类方法的发展,分析了MODIS影像在水稻种植面积遥感提取技术方面的研究进展及发展方向。结果表明：MODIS具有高光谱、高时间分辨率、多时相等特点,在大尺度上提取水稻种植面积上,可提高作物识别和监测的精确度与工作效率,节约成本,有着其他遥感数据无法相比的优势,应用MODIS数据提取水稻种植面积,取得了较好的效果。水稻遥感的最佳时相可以选择移栽期和孕穗期,利用对水体和植被较为敏感的波段或植被指数（如NDVI、LSWI和EVI）进行水稻识别,并提取种植面积。传统的遥感图像分类方法如监督分类和非监督分类,算法成熟、操作简单,是目前应用较多的方法;近年来发展起来的分类新方法,如决策树分类法、专家系统分类法、神经网络分类法,支持向量机法等,能够更准确地提取目标地物,对图像分类有不同程度的改进,在实际应用中通常和传统分类方法结合起来使用;多时相分析法与高时间、高分辨率多光谱影像的结合可以获取较高精度的作物种植面积数据,与传统分类方法相比有较大提高。利用MODIS对单一的或大面积的水稻种植面积提取效果较好,但对于地块破碎的种植面积估算尚难达到满意的结果,添加其他的辅佐数据如高程、坡度等,并结合MODIS数据的多时相特点分类等方法,可提高遥感影像分类的精度。 相似文献
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草地植被指数季节变化的遥感动态监测研究 总被引：1，自引：0，他引：1
利用EOS/MODIS卫星遥感数据,针对MODIS的应用特点,借鉴国内外基于遥感手段监测植被的方法以及植被指数的研究进展,探讨了草地变化动态监测的方式和方法。以乌鲁木齐地区为研究对象,用植被指数最大合成法,合成了该地区2004年4月至10月每个月的最大植被指数图。同时,利用每月合成的最大植被指数图,以乌鲁木齐南郊天山中段北坡的草地为典型研究区,通过典型区野外实地采样得到与MODIS影像资料时相一致的草地地上生物量数据,并利用ENVI软件提取出典型区各样点的植被指数值,分析了遥感植被指数与植被生物量的相关关系,从而建立起了植被指数在草甸和草原不同季节的生物量估测模型。 相似文献
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Observed daily precipitation data from the National Meteorological Observatory in Hainan province and daily data from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis-2 dataset from 1981 to 2014 are used to analyze the relationship between Hainan extreme heavy rainfall processes in autumn (referred to as EHRPs) and 10–30 d low-frequency circulation. Based on the key low-frequency signals and the NCEP Climate Forecast System Version 2 (CFSv2) model forecasting products, a dynamical-statistical method is established for the extended-range forecast of EHRPs. The results suggest that EHRPs have a close relationship with the 10–30 d low-frequency oscillation of 850 hPa zonal wind over Hainan Island and to its north, and that they basically occur during the trough phase of the low-frequency oscillation of zonal wind. The latitudinal propagation of the low-frequency wave train in the middle-high latitudes and the meridional propagation of the low-frequency wave train along the coast of East Asia contribute to the ‘north high (cold), south low (warm)’ pattern near Hainan Island, which results in the zonal wind over Hainan Island and to its north reaching its trough, consequently leading to EHRPs. Considering the link between low-frequency circulation and EHRPs, a low-frequency wave train index (LWTI) is defined and adopted to forecast EHRPs by using NCEP CFSv2 forecasting products. EHRPs are predicted to occur during peak phases of LWTI with value larger than 1 for three or more consecutive forecast days. Hindcast experiments for EHRPs in 2015–2016 indicate that EHRPs can be predicted 8–24 d in advance, with an average period of validity of 16.7 d. 相似文献
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Based on the measurements obtained at 64 national meteorological stations in the Beijing–Tianjin–Hebei (BTH) region between 1970 and 2013, the potential evapotranspiration (ET0) in this region was estimated using the Penman–Monteith equation and its sensitivity to maximum temperature (Tmax), minimum temperature (Tmin), wind speed (Vw), net radiation (Rn) and water vapor pressure (Pwv) was analyzed, respectively. The results are shown as follows. (1) The climatic elements in the BTH region underwent significant changes in the study period. Vw and Rn decreased significantly, whereas Tmin, Tmax and Pwv increased considerably. (2) In the BTH region, ET0 also exhibited a significant decreasing trend, and the sensitivity of ET0 to the climatic elements exhibited seasonal characteristics. Of all the climatic elements, ET0 was most sensitive to Pwv in the fall and winter and Rn in the spring and summer. On the annual scale, ET0 was most sensitive to Pwv, followed by Rn, Vw, Tmax and Tmin. In addition, the sensitivity coefficient of ET0 with respect to Pwv had a negative value for all the areas, indicating that increases in Pwv can prevent ET0 from increasing. (3) The sensitivity of ET0 to Tmin and Tmax was significantly lower than its sensitivity to other climatic elements. However, increases in temperature can lead to changes in Pwv and Rn. The temperature should be considered the key intrinsic climatic element that has caused the "evaporation paradox" phenomenon in the BTH region. 相似文献
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Storms that occur at the Bay of Bengal (BoB) are of a bimodal pattern, which is different from that of the other sea areas. By using the NCEP, SST and JTWC data, the causes of the bimodal pattern storm activity of the BoB are diagnosed and analyzed in this paper. The result shows that the seasonal variation of general atmosphere circulation in East Asia has a regulating and controlling impact on the BoB storm activity, and the “bimodal period” of the storm activity corresponds exactly to the seasonal conversion period of atmospheric circulation. The minor wind speed of shear spring and autumn contributed to the storm, which was a crucial factor for the generation and occurrence of the “bimodal pattern” storm activity in the BoB. The analysis on sea surface temperature (SST) shows that the SSTs of all the year around in the BoB area meet the conditions required for the generation of tropical cyclones (TCs). However, the SSTs in the central area of the bay are higher than that of the surrounding areas in spring and autumn, which facilitates the occurrence of a “two-peak” storm activity pattern. The genesis potential index (GPI) quantifies and reflects the environmental conditions for the generation of the BoB storms. For GPI, the intense low-level vortex disturbance in the troposphere and high-humidity atmosphere are the sufficient conditions for storms, while large maximum wind velocity of the ground vortex radius and small vertical wind shear are the necessary conditions of storms. 相似文献
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The spatial and temporal variations of daily maximum temperature(Tmax), daily minimum temperature(Tmin), daily maximum precipitation(Pmax) and daily maximum wind speed(WSmax) were examined in China using Mann-Kendall test and linear regression method. The results indicated that for China as a whole, Tmax, Tmin and Pmax had significant increasing trends at rates of 0.15℃ per decade, 0.45℃ per decade and 0.58 mm per decade,respectively, while WSmax had decreased significantly at 1.18 m·s~(-1) per decade during 1959—2014. In all regions of China, Tmin increased and WSmax decreased significantly. Spatially, Tmax increased significantly at most of the stations in South China(SC), northwestern North China(NC), northeastern Northeast China(NEC), eastern Northwest China(NWC) and eastern Southwest China(SWC), and the increasing trends were significant in NC, SC, NWC and SWC on the regional average. Tmin increased significantly at most of the stations in China, with notable increase in NEC, northern and southeastern NC and northwestern and eastern NWC. Pmax showed no significant trend at most of the stations in China, and on the regional average it decreased significantly in NC but increased in SC, NWC and the mid-lower Yangtze River valley(YR). WSmax decreased significantly at the vast majority of stations in China, with remarkable decrease in northern NC, northern and central YR, central and southern SC and in parts of central NEC and western NWC. With global climate change and rapidly economic development, China has become more vulnerable to climatic extremes and meteorological disasters, so more strategies of mitigation and/or adaptation of climatic extremes,such as environmentally-friendly and low-cost energy production systems and the enhancement of engineering defense measures are necessary for government and social publics. 相似文献
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《大气和海洋科学快报》2013,(1):67
正AIMS AND SCOPE Atmospheric and Oceanic Science Letters (AOSL) publishes short research letters on all disciplines of the atmosphere sciences and physical oceanography. Contributions from all over the world are welcome.SUBMISSIONAll submitted 相似文献
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<正>With the support of specialized funds for national science institutions,the Guangzhou Institute of Tropical and Marine Meteorology,China Meteorological Administration set up in October 2008 an experiment base for marine meteorology and a number of observation systems for the coastal boundary layer,air-sea flux,marine environmental elements,and basic meteorological elements at Bohe town,Maoming city,Guangdong province,in the northern part of the South China Sea. 相似文献
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《大气和海洋科学快报》2014,7(6):F0003-F0003
AIMS AND SCOPE
Atmospheric and Oceanic Science Letters （AOSL） publishes short research letters on all disciplines of the atmosphere sciences and physical oceanography. Contributions from all over the world are welcome. 相似文献
Atmospheric and Oceanic Science Letters （AOSL） publishes short research letters on all disciplines of the atmosphere sciences and physical oceanography. Contributions from all over the world are welcome. 相似文献
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《大气和海洋科学快报》2014,(5):F0003-F0003
AIMS AND SCOPE Atmospheric and Oceanic Science Letters （AOSL） pub- lishes short research letters on all disciplines of the atmos- phere sciences and physical oceanography. Contributions from all over the world are welcome. 相似文献
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《大气和海洋科学快报》2012,(3):273
正AIMS AND SCOPE Atmospheric and Oceanic Science Letters (AOSL) publishes short research letters on all disciplines of the atmosphere sciences 相似文献