卫星遥感反演土壤水分研究综述   总被引：12，自引：1，他引：11  

陈书林  刘元波  温作民 《地球科学进展》2012,27(11):1192-1203

土壤水分是影响地表过程的核心变量之一。精准地测量土壤水分及其时空分布,长期以来是定量遥感研究领域的难点问题。简要回顾基于光学、被动微波、主动微波和多传感器联合反演等卫星遥感反演土壤水分的主要反演算法、存在的难点和前沿性研究问题,介绍了应用土壤水分反演算法所形成的3种主要全球土壤水分数据集,包括欧洲气象业务卫星（ERS/MetOp）数据集、高级微波扫描辐射计（AMSR-E）数据集、土壤湿度与海洋盐分卫星（SMOS）数据集,并结合目前存在的问题探讨卫星遥感反演土壤水分研究的发展趋势。  相似文献   

应用WS/GPS技术的粪渣收运监控系统的开发     

钟波 《地理空间信息》2011,(6):45-46,54

通过安装于粪渣收运车辆上的车载称重系统（WS）和全球卫星定位系统（GPS）,经由通用无线分组业务（GPRS）将粪渣收运车载重变化及其位置信息,实时传回监控中心的数据库中[1],并通过集成地理信息系统（GIS）的粪渣收运监控系统浏览、查询、管理粪渣收运情况。主要以车载重量变化信息作为收运监控参考的重要依据,并配合车辆定位...  相似文献   

利用激光雷达资料分析兰州远郊气溶胶光学特性   总被引：9，自引：1，他引：8       下载免费PDF全文

周碧  张镭  曹贤洁  韩霄  张武  冯广泓 《高原气象》2011,30(4):1011-1017

利用2007年1～4月兰州大学半干旱气候与环境观测站激光雷达资料,反演了晴空无云典型日和沙尘过程大气气溶胶消光系数和光学厚度。结果表明,兰州远郊榆中地区,1km以下大气气溶胶消光系数较大,为0.01～0.1km-1;平均气溶胶光学厚度〈0.5,光学厚度日变化呈双峰型,峰值分别出现在12：00和20：00。采暖期与非采暖...  相似文献   

《震灾防御技术》第6卷(2011年)总目录     

《震灾防御技术》2011,6(4):478-480

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基于DTU的加速度强振动记录终端的设计     

吴林斌  陈志高  关伟智  吕瀚  李家明  吴雄伟 《大地测量与地球动力学》2011,31(Z1):155-156,164

设计基于DTU的强振记录终端,采用SOC系列C8051F015型单片机对MEMS加速度计的输出信号进行A/D转换,监测待测体所经受的强振加速度值,并通过DTU内嵌的GPRS无线网络通讯方式将数据发送到远程数据中心.该系统具有体积小,安装与操作方便,免维护等特性.  相似文献   

Geochemical monitoring of clays for diagenetic evolution of the Paleozoic–Lower Mesozoic sequence in the northern Arabian plate: Hazro and Amanos regions,Southeastern Turkey     

《Journal of African Earth Sciences》2013

Clay minerals in the diagenetic/very low-grade metamorphic–sedimentary series from southeastern Anatolia in Turkey were analyzed to determine their mineralogical and chemical compositions. In the Amanos region, the lowermost unit is composed of metaclastics with primary clastic textures, as well as slaty cleavages and chlorite-mica stacks including volcanic rock intercalations. The Lower Cambrian is composed of mainly very low-grade metamorphic clastic rocks, while the Ordovician units have siliciclastic and carbonate rocks. In the Hazro region, the Late Silurian–Lower Triassic units are represented by highly diagenetic carbonate and clastic rocks. All of the rock units include illite. In addition, chlorite, mixed-layered illite–chlorite and chlorite–vermiculite are present in the Amanos region, while calcite, dolomite, kaolinite, mixed-layered illite–smectite (I–S) and glauconite occur in the Hazro region. The illites are characterized by the dominance of 2M₁ polytype in the Amanos samples; and 1M_d + 2M₁ in the Hazro samples. The I–S, glauconite and kaolin have R1 and R3, 1M and kaolinite polytypes, respectively. The illites have greater tetrahedral and lower octahedral substitutions than the I–S. Total trace element contents, elemental substitutions and chondrite-normalized trace element and REE values decrease toward illite–I–S–kaolinite. There are obvious fractionations for some major – trace and rare earth elements with respect to each other and clear enrichment with respect to the chondrite, with strong anomalies of positive for Gd and negative for P, K and Eu in the clay minerals. The textural, morphological and geochemical data indicate that kaolinite and I–S in the Hazro area occur in supergene conditions with due to a full neoformation mechanism, whereas illites in the Amanos region represent the hypogene origin. In brief, the K₂O contents, ratios of Eu/Eu^* and La_N/Lu_N and δ¹⁸O and δD values of I–S and illite exhibit notable relationships with increasing diagenetic/metamorphic grade.  相似文献   

地震叠前时间偏移的一种图形处理器提速实现方法   总被引：25，自引：11，他引：14       下载免费PDF全文

李博  刘国峰  刘洪 《地球物理学报》2009,52(1):245-252

新近发展的图形处理器（GPU,Graphic Processing Unit）通用计算技术,现已日趋实用成型,并获得诸多应用领域的广泛关注.对油气勘探专项资料处理技术的运用而言,概因GPU与中央处理器（CPU）的计算性能的甚大差异,致使GPU这一通用计算技术在石油工业中的应用研究正在有效开展.本文仅借助于油气勘探中广泛使用的叠前时间偏移,旨在于扼要阐明其基于GPU应用的有效性;文中还提出一种利用GPU实现地震叠前时间偏移的软件构件方法,并针对非对称走时叠前时间偏移所拓展的应用软件提供一种具体实现架构.与以往用个人计算机（PC,Personal Computer）或者PC集群所用的叠前时间偏移相比,本文方法可甚大地提高计算效率,从而在石油物探资料处理中可显著地节约计算成本和维护费用.文中实际例证也表明,基于GPU进行高性能并行计算,当是适应目前石油工业中大规模计算需求的一个重要发展途径.  相似文献   

Dating of Late Pleistocene terrace deposits of the River Rhine using Uranium series and luminescence methods: Potential and limitations     

Stphane Kock  Jan D. Kramers  Frank Preusser  Andreas Wetzel 《Quaternary Geochronology》2009,4(5):363-373

Uranium-series dating of pedogenic carbonate crusts from fluvial gravels is tested using Optically Stimulated Luminescence (OSL) ages as references. OSL dating yielded ages of 30–15 ka and 13–11 ka, which correlate with the cold periods of the Last Glacial Maximum and the Younger Dryas. These ages are internally coherent and consistent with the geological background and are thus regarded as reliable. Most of the U/Th results scatter widely in the ²³⁰Th/²³²Th vs. ²³⁴U/²³²Th isochron diagram, making regression unrealistic. Semiquantitative age estimates from the data were found to be mostly older than the OSL ages and the geological context. It is suggested that a heterogeneous initial ²³⁰Th input, not relatable to a detrital component, is responsible for the observed discrepancies. This input may be due to bacterial activities and Th transport on organic colloids. It appears necessary to avoid samples where bacteria could have contributed to carbonate precipitation. Further, the relative importance of this problem decreases with sample age, so that U/Th dating of sinters is expected to be more reliable in the >100 ka age range.  相似文献   

Late Holocene dune activity in the Eastern Platte River Valley, Nebraska     

P.R. Hanson  R.M. Joeckel  A.R. Young  J. Horn 《Geomorphology》2009,103(4):555-561

Large-scale dune activity in the Nebraska Sand Hills and elsewhere on the western Great Plains has been linked to prehistoric “megadroughts” that triggered the activation of regional dune fields. The effect of megadroughts on the smaller dune fields east of the Nebraska Sand Hills has never been assessed, however. This study focuses on the Duncan dune field near the confluence of the Loup and Platte rivers in eastern Nebraska. Seventeen optically stimulated luminescence age estimates were obtained and reveal two periods of dune activation that occurred between 4.4 to 3.4 ka and 0.8 to 0.5 ka. Significantly, both periods chronologically overlap large-scale dune activity identified in the Nebraska Sand Hills. Geochemical evidence indicates that the Duncan dunes received sand not only from the terrace underlying them, but also from the Loup River. These data link dune activity in the Duncan area, at least indirectly, to increased sediment supply from streams that drain the Sand Hills during megadroughts, implying the activation of the dunes occurred as an indirect response to regional megadroughts. Calculations of dune migration rates, however, argue in favor of local, drought-driven hydrologic changes as a causative factor in dune activation, in other words, a direct effect of megadroughts. Whether the impact was direct or indirect, it is highly likely that the repeated reactivation of the Duncan dunes resulted in some way from regional, large-magnitude droughts. Other paleoclimate proxies from the Great Plains tend to support this conclusion. We conclude that the megadroughts that have been identified in the Sand Hills and other Great Plains dune fields were indeed regional events with far-reaching effects.  相似文献   

极端干旱区荒漠稀疏河岸林遥感分类研究   总被引：5，自引：0，他引：5  

古丽·加帕尔  陈曦  马忠国  常存 《中国沙漠》2009,29(6):1153-1161

研究以位于极端干旱区的塔里木河干流中下游地区为例,基于Landsat TM影像,结合决策树分类、几何光学模型与光谱角匹配,解决混合像元信息分解,实现干旱区稀疏荒漠河岸林类别识别。首先从遥感视角的角度,将地物分解为目标和背景,提出塔里木河干流荒漠河岸林植被分类系统;其次以多变量决策树法将非荒漠植被信息剔除,采用几何光学模型模拟各类荒漠植被的像元光谱,最后以光谱角匹配的方法将荒漠植被进一步进行分解,得到塔里木河干流中下游地区典型研究区的植被分类专题图,分类精度结果表明:基于混合像元分解与几何光学模型的分类方法总精度达到了79.43%,Kappa系数为0.718,表明分类质量良好。  相似文献