多尺度细节增强的遥感影像超分辨率重建     

朱红  宋伟东  谭海  王竞雪 《测绘学报》2016,45(9):1081-1088

鉴于现有超分辨率重建方法难以突显重建影像细节信息的问题,提出多尺度细节增强的遥感影像超分辨率重建模型框架。首先,通过最小二乘滤波方法将序列影像分解成包含大尺度边缘的平滑信息和包含中小型尺度的细节信息;其次,利用插值方法得到相应的高分辨率细节信息和平滑信息,构造纹理细节增强函数,提升中小型细节的增强幅度;最终,融合细节信息和平滑信息,得到初始的超分辨率重建结果,并利用局部优化模型进一步改善重建影像质量。选取同时相和多时相遥感影像作为试验数据。试验结果表明,本文重建结果与插值方法、TV方法和MAP方法相比,在客观评价指标上均有显著提高,明显改善了重建影像的纹理细节。论文提出的多尺度细节增强的超分辨率重建方法,可以使重建影像提供更多高频细节信息,具有较好鲁棒性和普适性。  相似文献   

遥感影像超分辨率处理方法与研究进展   总被引：1，自引：1，他引：0  

陆婉芸  王继周 《测绘科学》2016,41(12):53-58,69

随着人们对影像高分辨率需求的不断增加,图像超分辨率技术已成为相关研究领域的热点之一。针对在遥感领域并非所有的超分辨率方法都可用的现状,该文按照遥感影像超分辨率处理的流程,将超分辨率问题分为退化模型、配准、重建和精度评定4大模块。对于其中每一模块的理论、常用方法与研究进展进行了较全面的综述及比较分析。最后对这一领域的未来发展进行思考和展望。  相似文献   

扬子西缘乡城-丽江结合带燕山期斑岩Mo多金属矿床成矿系统   总被引：5，自引：3，他引：2  

刘学龙  李文昌  张娜  赖安琦  李喆  杨富成 《岩石学报》2016,32(8):2281-2302

位于扬子陆块西缘与西南三江造山带结合部位的乡城-丽江地区,北起四川乡城经云南格咱南至丽江地区,在印支期斑岩铜矿带上新发现叠加了燕山期斑岩Mo多金属成矿作用,形成乡城-丽江斑岩Mo矿带。受印支期古特提斯洋盆闭合后地壳缩短与加厚的影响,燕山晚期下地壳发生拆沉作用,导致后碰撞型花岗质岩浆侵位,发育了Mo多金属成矿作用,并构成斑岩成矿系统。岩石地球化学特征表明,燕山晚期含矿斑岩具高硅(SiO_2=66.29%~79.36%)、高碱(K_2O+Na_2O=5.07%~9.24%)、富钾(K_2O/Na_2O=0.71~2.13)的特点,属于高钾钙碱性岩石系列。岩石富集轻稀土元素(LREE),具有负δEu异常;微量元素具富集大离子亲石元素K、U、Th、Rb,亏损高场强元素Nb、Ta、P、Ti的特征;大离子亲石元素的富集和Nb、Ta等高场强元素的亏损,表明形成这些岩体的岩浆主要来自地壳,具有造山带花岗岩的地球化学特征。区内代表性含矿斑岩相似的地球化学组成及分布特征表明,乡城-丽江结合带燕山晚期的成矿斑岩是由同源岩浆分异演化而来。成矿系统的分析表明,燕山晚期主要含矿斑岩成矿物质以壳源为主,但具有少量地幔物质的加入,成岩成矿物质来源具有相似或一致的源区特征。在成矿元素的组合上,由成矿斑岩体向外带表现出W、Mo→W、Mo、Cu→Pb、Zn、Ag的演化趋势。研究表明,本区燕山晚期花岗岩浆的侵入及Mo多金属成矿作用并不是独立或个别的成矿事件,而是纵跨义敦岛弧、甘孜-理塘结合带及扬子西缘的带状成矿活动,属于区内与燕山晚期岩浆侵入作用相关的统一斑岩成矿系统。  相似文献   

Geochemical characteristics of the Paleogene shales in the Dongying depression,eastern China     

《Marine and Petroleum Geology》2016

Fluctuations in lacustrine sedimentary environments significantly affect distributions of organic matter (OM), uranium, and other elements in shales. In this study a high-resolution geochemical record of fluctuations in the paleo-depositional environment of a terrestrial lake basin is provided on the basis of extensive samples collected from the Member 3 of the Paleogene Shahejie Formation (Es₃) of the Niu-38 well in the Dongying Depression, Eastern China. These samples were tested for total organic carbon (TOC), element concentrations, and biomarkers to study the evolution and fluctuation in the depositional environments of an ancient lake basin and associated geochemical response. The evolution and fluctuation of the sedimentary environment from a deep lake to a semi-deep lake and then to a shallow lake delta were indicated by geochemical response. During this evolution, the values of TOC, S₁, S₂, Sr, and Ts/(Ts + Tm) remarkably decreased, whereas those of Co, Ni, Rb, Na, Fe/Mn, Fe/(Ca + Mg), and C₂₉ mortane/C₂₉ hopane significantly increased. The deep lake basin shows depositional fluctuations, as indicated by rock lithofacies and their geochemical parameters. A close interrelationship was observed among U concentration, TOC content, and inorganic element content. Uranium concentrations are positively correlated with TOC contents, Ca and Sr concentrations, and Sr/Ba and Ca/Mg ratios but negatively with K, Na, Ba, and Rb contents and Fe/(Ca + Mg) and Fe/Mn ratios. The observed increase in U concentration in the lower Es₃ section is closely related to surface adsorption by clay minerals and OM, together with some replacements of Ca and Sr by U in the shales.  相似文献   

Fusing MODIS with Landsat 8 data to downscale weekly normalized difference vegetation index estimates for central Great Basin rangelands,USA   总被引：1，自引：0，他引：1  

Stephen P. Boyte  Bruce K. Wylie  Matthew B. Rigge  Devendra Dahal 《地理信息系统科学与遥感》2018,55(3):376-399

Data fused from distinct but complementary satellite sensors mitigate tradeoffs that researchers make when selecting between spatial and temporal resolutions of remotely sensed data. We integrated data from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor aboard the Terra satellite and the Operational Land Imager sensor aboard the Landsat 8 satellite into four regression-tree models and applied those data to a mapping application. This application produced downscaled maps that utilize the 30-m spatial resolution of Landsat in conjunction with daily acquisitions of MODIS normalized difference vegetation index (NDVI) that are composited and temporally smoothed. We produced four weekly, atmospherically corrected, and nearly cloud-free, downscaled 30-m synthetic MODIS NDVI predictions (maps) built from these models. Model results were strong with R² values ranging from 0.74 to 0.85. The correlation coefficients (r ≥ 0.89) were strong for all predictions when compared to corresponding original MODIS NDVI data. Downscaled products incorporated into independently developed sagebrush ecosystem models yielded mixed results. The visual quality of the downscaled 30-m synthetic MODIS NDVI predictions were remarkable when compared to the original 250-m MODIS NDVI. These 30-m maps improve knowledge of dynamic rangeland seasonal processes in the central Great Basin, United States, and provide land managers improved resource maps.  相似文献   

Resistivity of reservoir sandstones and organic rich shales on the Barents Shelf:Implications for interpreting CSEM data     

Kim Senger  Thomas Birchall  Peter Betlem  Kei Ogata  Sverre Ohm  Snorre Olaussen  Renate S.Paulsen 《地学前缘(英文版)》2021,12(6):411-427

Marine controlled source electromagnetic(CSEM)data have been utilized in the past decade during petroleum exploration of the Barents Shelf,particularly for de-risking the highly porous sandstone reservoirs of the Upper Triassic to Middle Jurassic Realgrunnen Subgroup.In this contribution we compare the resistivity response from CSEM data to resistivity from wireline logs in both water-and hydrocarbon-bearing wells.We show that there is a very good match between these types of data,particularly when reservoirs are shallow.CSEM data,however,only provide information on the subsurface resistivity.Careful,geology-driven interpretation of CSEM data is required to maximize the impact on exploration success.This is particularly important when quantifying the relative re-sistivity contribution of high-saturation hydrocarbon-bearing sandstone and that of the overlying cap rock.In the presented case the cap rock comprises predominantly organic rich Upper Jurassic-Early Cretaceous shales of the Hekkingen Formation(i.e.a regional source rock).The resistivity response of the reservoir and its cap rock become merged in CSEM data due to the transverse resistance equivalence principle.As a result of this,it is imperative to understand both the relative contributions from reservoir and cap rock,and the geological sig-nificance of any lateral resistivity variation in each of the units.In this contribution,we quantify the resistivity of organic rich mudstone,i.e.source rock,and reservoir sandstones,using 131 exploration boreholes from the Barents Shelf.The highest resistivity(＞10,000 Ωm)is evident in the hydrocarbon-bearing Realgrunnen Subgroup which is reported from 48 boreholes,43 of which are used for this study.Pay zone resistivity is primarily controlled by reservoir quality(i.e.porosity and shale fraction)and fluid phase(i.e.gas,oil and water saturation).In the investigated wells,the shale dominated Hekkingen Formation exhibits enhanced resistivity compared to the background(i.e.the underlying and overlying stratigraphy),though rarely exceeds 20Ωm.Marine mudstones typically show good correlation between measured organic richness and resistivity/sonic velocity log signatures.We conclude that the resistivity contribution to the CSEM response from hydrocarbon-bearing sandstones out-weighs that of the organic rich cap rocks.  相似文献   

不同要素谱逼近对高分辨区域数值模式梅雨模拟的改进   总被引：1，自引：0，他引：1  

董美莹  陈锋  冀春晓 《气象》2019,45(5):593-605

为改进高分辨率区域数值天气预报模式雨带模拟偏差,利用WRF模式探讨了不同要素及其组合谱逼近方法对2015年浙江典型梅雨天气预报性能的影响。结果表明:(1)不同单要素逼近对梅雨模拟效果影响差异明显,风场逼近对模拟结果改进较大,高度场逼近对结果略有改善,而温度场逼近主要表现为负效应;风场组合了其他要素的逼近效果与单要素类似,故将水平风场谱逼近确定为最优方案。(2)最优方案对梅雨期间形势场各要素改进程度的排序为纬向风、经向风、相对湿度、温度场和高度场;三个特征层850、500、200 hPa各要素平均的均方根误差(相关系数)分别降低了(增加了)24. 1%(13.6%)、22.7%(21.7%)和13.0%(12.2%);且改进幅度随预报时效的延长而增加,这主要与区域模式内部大尺度系统的误差随积分时间增长有关。(3)典型个例分析显示,最优方案在较好订正低层风场及切变线动力条件的基础上,经过数值模式各物理过程的协同积分也修正了高湿区等关键热力因子,最终改进了高分辨率区域模式的梅雨模拟。  相似文献   

基于不同分辨率和参数化方案的新疆区域数值模式性能初步评估     

杜娟  李曼  于晓晶  辛渝 《沙漠与绿洲气象(新疆气象)》2019,(3):57-65

基于中尺度数值模式WRF,选取新疆两次强降水过程,设计3个试验方案,其中试验1为控制试验,试验2提高分辨率,试验3提高分辨率并调整物理参数化方案,初步评估不同分辨率和参数化方案对新疆区域2m温度、10m风速、降水预报的影响。结果表明:(1)提高分辨率对2m温度、10m风速模拟精度均有提高,2m温度预报精度提高约0.5℃,降低了日间温度模拟冷偏差;10m风速预报精度提高约0.5m/s,降低了风速模拟正偏差;但提高分辨率后,模式出现虚假降水预报的情况。(2)提高分辨率并调整物理参数化方案后,2m温度模拟误差略有减小,模拟偏差减小约0.2℃;10m风速模拟误差增大约0.5m/s,模拟偏差增大超过0.5m/s;对降水落区、量级的模拟精度显著提高,减小了降水中心的模拟强度,对虚假降水预报有一定修正。  相似文献   

姚安地震序列与大姚地震序列震源参数的对比研究   总被引：6，自引：0，他引：6  

刘丽芳  刘杰  苏有锦 《地震》2006,26(1):10-18

2000年1月15日在云南省姚安县发生了M_S6.5地震, 2003年7月21日和10月16日在云南省大姚县发生了M_S6.2、 M_S6.1地震。 这两个地震序列均发生在滇中块体, 震中位置相距42.5 km, 构造、 应力背景相似, 但序列类型不同, 时间间隔短。 为深入研究姚安地震和大姚地震序列的特征, 根据昆明区域数字台网记录的数字地震波资料, 利用遗传算法计算了2000年姚安地震和2003年大姚地震序列的震源参数。 研究结果表明, 姚安地震序列和大姚地震序列的地震矩和近震震级有很好的线性关系, 它们的地震矩M₀均在10¹²~10¹⁴ N·m, 地震矩与震源半径之间呈线性关系。 应力降随震级变化不明显。 拐角频率和地震矩之间有明显的依赖关系, 用最小二乘法拟合拐角频率和地震矩的关系式, 利用此关系式可计算出给定地震矩的拐角频率估计值f_a, 进而可分析实际计算的拐角频率与估计值之差(f_c-f_a)的时间变化曲线。 姚安地震序列和大姚地震序列实际计算的拐角频率与估计值之差(f_c-f_a)及应力降随时间的变化表现出了不同的特征: 姚安地震序列的应力降和拐角频率差值在4.3级和4.6级强余震前均有一个上升-下降过程, 反映余震区应力场有一个增高-下降过程; 大姚地震序列应力降和拐角频率差值在M_S≥4.6强余震发生之前均会出现高值异常, 但在M_S4.6～4.7地震之前出现的高值异常持续时间短, 在M_S6.1地震前出现的高值异常持续较长。 文中结合两个地震的发震构造, 序列类型等特征进行了分析讨论。  相似文献   

城市居住单元环境质量的高分辨率遥感评价方法研究   总被引：5，自引：0，他引：5  

程承旗  李启青  沙志友  郭仕德 《地球科学进展》2006,21(1):24-30

高分辨率遥感影像由于其较高的空间分辨率使得在居住单元的尺度上进行城市环境质量的遥感评价成为可能。所研究的评价方法在选取传统的环境评价指标如绿地景观结构参数、建筑容积率参数基础上,提出了平均可视面积、影像地物交替复杂度以及山体、水体、绿地、道路等外界地物影响力等指标,进一步研究了相关指标的分析方法。最后采用模糊评判的方法得到各参数指标的评判矩阵,进一步获得各居住单元综合指标评价的最终结果。使用厦门市QuickBird遥感影像进行了相关评价方法的实验,对8个典型居住单元的环境评价实验研究表明,利用高分辨率影像进行城市人居环境质量评价是一种成本较低、简便可行的方法。  相似文献