基于遥感影像的卫星颤振探测分析的关键技术与实现     

王凤香  刘世杰  童小华  唐新明  徐聿升  叶真  李凌云  谢俊峰  李天鹏  洪中华 《地球信息科学学报》2015,17(6):724-731

姿态颤振是高分辨率卫星普遍存在的复杂现象,随着卫星的复杂性和敏捷性的提高,故其对成像质量的影响机制和相应的探测与补偿方法,成为高分辨率卫星对地观测研究的关键问题。本文介绍了基于遥感影像的卫星颤振探测原理和关键技术,利用传感器的构造特点,通过不同波段的多光谱影像,以及不同视角的全色立体影像间的密集匹配精确量测和获取影像视差差异值,反演卫星姿态颤振的规律和特性,从而对规律性的颤振现象进行建模和补偿。鉴于上述理论,在Visual C++的平台下,研制了卫星颤振探测分析系统,设计了以计算机性能优化的图像分块并行算法。测试结果表明,该软件能有效探测出0.1像元偏移的卫星姿态颤振,并可对规律性颤振进行建模和补偿,有较好的稳定性和并行效率。其已成功应用于资源三号卫星地面应用系统,并可扩展于其他卫星系统的颤振探测分析。  相似文献   

基于空间抽样的区域地表覆盖遥感制图产品精度评估——以中国陕西省为例     

孟雯  童小华  谢欢  王振华 《地球信息科学学报》2015,17(6):742-749

地表覆盖数据是研究气候变化、生态环境、地理国情和人文经济等方面不可或缺的基础信息,因此其质量的优劣将直接影响相关决策的可靠性。本文针对我国研制的首套30 m分辨率全球地表覆盖数据产品,通过分析其海量、多维、非均质等空间特点,对传统的制图产品精度评估方法提出了改进：以地表类型进行分层抽样,样本量的计算采用优化模型并以地类所占面积比为权重逐层分配,样本的布设则考虑层内对象之间的空间相关性,在地表数据自然分布的基础上,通过分析空间相关性指数来提高样本的代表性和精度评估结果的可靠性。因此,本文提出针对区域地表覆盖遥感制图产品的空间分层抽样方法,其将精度评估分成抽样方案（样本的定量估计）和布设方案（样本的空间布设）2个部分,并以中国陕西省地表覆盖产品为例进行区域精度评估实验分析,从全区7大类地表类型数据中抽取1467个样本,经过样本检验与精度计算,该区域产品的总体精度为79.96%,Kappa系数为0.74。实验结果表明,本文提出的基于空间抽样的精度评估方法可行可靠,实验区域产品质量较好,并为后续针对全球范围的地表覆盖产品精度评估方法提供了参考。  相似文献   

激光跟踪仪测量精度分析     

孙海丽  姚连璧  周跃寅  孙盼盼 《大地测量与地球动力学》2015,35(1):177-181

以API公司的T3激光跟踪仪为例,进行简要的理论分析。通过校准前后对比实验、固定点重复测量、距离重复测量实验、激光跟踪仪和干涉仪对比实验、现场点位中误差测量实验及激光跟踪仪与常规测量对比实验,对激光跟踪仪的测量精度进行测量和验证。激光跟踪仪在校准后,短距离测量时测距精度对空间点位精度起主导作用,测角精度比较稳定;随着距离的增大,测距、空间点位误差增大。较之常规测量,短距离测量具有很高的测量精度。  相似文献   

Nonlinear dynamic analysis of multi-base seismically isolated structures with uplift potential Ⅱ: verification examples     

Panayiotis C. Roussis  Panos C. Tsopelas  Michael C. Constantinou 《地震工程与工程振动(英文版)》2010,9(1)

  相似文献   

Accuracy assessments and uncertainty analysis of spatially explicit modeling for land use/cover change and urbanization:A case in Beijing metropolitan area     

ZHANG Jie    ZHOU YinKang  LI RenQiang  ZHOU ZhaoJun  ZHANG LiQuan  SHI QingDong & PAN XiaoLing State Key Laboratory of Estuarine  Coastal Research  East China Normal University  Shanghai  China  College of Geography  Ocean Sciences  Nanjing University  Nanjing  Research Center for Ecosystem Network 《中国科学:地球科学(英文版)》2010,(2)

Spatially explicit modeling plays a vital role in land use/cover change and urbanization research as well as resources management;however,current models lack proper validation and fail to incorporate uncertainty into the formulation of model predictions.Consequently,policy makers and the general public may develop opinions based on potentially misleading research,which fails to allow for truly informed decisions.Here we use an uncertainty strategy of spatially explicit modeling combined with the series stat...  相似文献   

云南2009年雨季T639、日本、德国3个数值模式的降水预报检验     

张秀年  曹杰  杨素雨 《云南地理环境研究》2010,22(6):15-19,23

对云南2009年雨季T639、日本、德国3个数值模式的降水预报进行了检验与比较,发现3个模式的降水预报均有明显的特征。总体偏差分析表明T639模式降水预报明显偏多,德国模式明显偏少,日本模式预报稍偏多。降水分级检验表明小雨和中雨的TS评分日本模式最高,大雨和暴雨的TS评分T639模式最高。T639和日本模式在降水的落区预报上均为正相关,对降水落区预报有一定的指导意义。总体上,3个模式中日本模式预报较准确,T639次之,德国模式的各项检验指标均为最低。  相似文献   

民国初期河南省1∶10万地图精度分析     

孔云峰 《地球信息科学学报》2011,13(2):226-233

 清末与民国初期调绘了大范围的、内容较为详尽的1 ∶2.5万至1 ∶20万比例尺地图,是研究20世纪初中国历史的宝贵资料。为高效利用这些地图资源,评估地图精度提供了基础性的图件。针对民国初期河南陆地测量局调绘的1 ∶10万河南省地图,应用ArcGIS软件将民国地图与当代地图作对比,对其精度进行了系统分析和初步解释。分析表明:①全省范围内地图精度分布不均匀,经线方向平均向西偏移6.28'、纬线方向平均向南移2.23',标准差分别为3.76和2.51。②纬线方向绝对精度和相对精度总体上高于经线方向;同时,误差分布呈现空间自相关特征,经向误差Moran's I指数为0.85(Z=57),纬向指数为0.69(Z=46)。③平原地区地图相对精度高于山区。④地图误差分布呈现三种模式:位置偏移较小,偏移较大但偏移向量保持一致,以及偏移较大且方向不一致。民国地图误差与《清史稿》记载的经纬度误差具有较强的相关性,由此提出的一个初步推论:民国地图调查作业中采用了晚清时期的经纬度成果。但有些地区利用了较新的成果,也有部分地区参照或转绘了质量较差的旧地图。本研究为民国初期河南省地图的进一步利用提供了依据,也对同期地图的利用具有借鉴价值。  相似文献   

How do GPM and TRMM precipitation products perform in alpine regions? A case study in northwestern China’s Qilian Mountains     

Sun  Weijun  Chen  Rensheng  Wang  Lei  Wang  Yingshan  Han  Chuntan  Huai  Baojuan 《地理学报(英文版)》2022,32(5):913-931

Journal of Geographical Sciences - Satellite technologies provide valuable areal precipitation datasets in alpine mountains. However, coarse resolution still limits the use of satellite...  相似文献   

广利河口拦门沙治理的试验研究--模型设计与验证     

孙国峰  陈兆林  拾兵 《海岸工程》2004,23(2):15-18

基于广利河口水文、地形、地貌及潮汐条件,设计和制作了一个变率为8、水平比尺为400的平面模型。模型地形表面经球体梅花型布置加糙后,再现了天然潮汐及河道径流过程．其主要控制点潮位、流速、流向变化过程与原形实测资料吻合良好。  相似文献   

Accuracy of Laser Ablation U-Pb Zircon Dating: Results from a Test Using Five Different Reference Zircons   总被引：2，自引：0，他引：2  

Urs Klötzli  Eva Klötzli  Zekeriya Günes  Jan Kosler 《Geostandards and Geoanalytical Research》2009,33(1):5-15

Using a state‐of‐the‐art 193 nm‐LA‐MC‐ICP‐MS system and with careful control of analytical procedures, the long term external reproducibility and accuracy of the ages Phanerozoic zircons measured over a period of months using calibrator bracketing for the ²⁰⁶Pb/²³⁸U and ²⁰⁷Pb/²⁰⁶Pb ages were ca. 1% (2 RSD) if a single reference zircon was used for the matrix‐matched calibration. When different reference zircons were used for the calibration, suspicious systematic shifts in the obtained ages were observed and thus a reduction in the overall accuracy of the dating method became obvious. Such shifts were within a few percent range of the U‐Pb and Pb/Pb ages and seemed to vary independently of zircon age and composition. A “test of accuracy” experiment was conducted reducing instrumental effects as far as possible by analysing five different reference zircons mounted on a single mount eight times during the same session. An identical protocol was used for all analyses, with unchanged instrument parameters and with ion beam intensities kept as identical as possible. For data reduction, every zircon served consecutively as the reference zircon for calibration, with the others in the batch treated as unknowns. The known reference age and the four calculated ages obtained using the four other RMs for calibration were then compared. Even using such a strict analytical protocol, shifts in ²⁰⁶Pb/²³⁸U, ²⁰⁷Pb/²³⁵U and ²⁰⁷Pb/²⁰⁶Pb ratios were still present. They varied non‐systematically and ranged from ?4.35% to 3.08% for the investigated age range (1065 Ma to 226 Ma). Assuming the absence of instrumental effects (i.e., memory, dead‐time correction, non‐linearity of ion counters and interdetector calibration, crystallographic orientation, ablation cell geometry and setup, gas flows), the observed shifts were attributed to matrix and/or ablation related effects. It is proposed that non‐spectral matrix effects in the Ar plasma torch resulted in non‐uniform signal enhancement (or depression?) leading to shifts both in elemental and Pb isotopic ratios. Additionally, the ablated particle size distribution could be an important factor controlling plasma conditions and thus mass bias and fractionation. Until such effects are well understood and controlled, it would seem that any LA‐ICP‐MS zircon U‐Pb and ²⁰⁷Pb/²⁰⁶Pb age determination cannot be meaningfully interpreted at below a ca. 3% to 4% (2 RSD) confidence level.  相似文献