共查询到19条相似文献，搜索用时 230 毫秒
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高光谱遥感影像维数高、数据量大、波段之间的相关性强,分类时易出现"Hughes"现象,因此在分类过程中如何有效减小数据处理过程中的计算量,又保证原始数据重要的地物信息不丢失具有重要的意义。压缩感知理论可通过远低于耐奎斯特的采样率和少量观测数据实现信号的精确重构,具有对硬件读写要求低、图像恢复效果好等优势。通过利用基于小波变换的压缩感知算法对黄河口地区的高光谱影像进行图像重构,然后分别采用SVM算法、最大似然法以及神经网络分类法对重构后的影像进行分类,并对分类结果的精度分别从空域和小波域、不同的测量值等维度进行了分析和比较。结果表明:(1)压缩感知理论重构后的影像保留了原始影像的基本信息,保证了分类精度;(2)SVM算法的分类精度最好,空域和小波域的分类精度基本一致;(3)分类精度随测量值的增加先逐渐提高,然后趋于稳定。 相似文献
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基于旋翼无人机雷达的船只目标成像与类型识别研究进展综述 总被引：1，自引：0，他引：1
载有成像雷达的旋翼无人机具有成本低廉、对起降条件要求低、飞行姿态灵活多样等优点，可以在热点区域进行普查、详查或长时间悬停凝视等多模式成像监测，现已成为海上船只目标监测识别的重要手段。本文分别从旋翼无人机雷达硬件系统、无人机载雷达动目标成像、船只目标类型识别和目标三维结构特征提取等四方面开展国内外研究进展综述。总结分析发现当前利用旋翼无人机雷达进行船只目标成像和类型识别，尚存在运动船只成像散焦、三维结构重建难度大、类型识别精度低等问题，迫切需要推动相关技术的发展。 相似文献
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4D analogue modelling of transtensional pull-apart basins 总被引：3，自引：0，他引：3
Jonathan E. Wu Ken McClay Paul Whitehouse Tim Dooley 《Marine and Petroleum Geology》2009,26(8):1608-1623
Scaled sandbox models were used to investigate the 4D evolution of pull-apart basins formed above underlapping releasing stepovers in both pure strike-slip and transtensional basement fault systems. Serial sectioning and 3D volume reconstruction permitted analysis of the full 3D fault geometries. Results show that very different pull-apart basins are developed in transtension compared to pure strike-slip. Both types of models produced elongate, sigmoidal to rhomboidal pull-apart systems, but the transtensional pull-apart basins were significantly wider and uniquely developed a basin margin of en-echelon oblique-extensional faults. Dual, opposing depocentres formed in the transtensional model whereas a single, central depocentre formed in pure strike-slip. In transtension, a distinct narrow graben system formed above the principal displacement zones (PDZs). Cross-basin fault systems that linked the offset PDZs formed earlier in the transtensional models.Sequential model runs to higher PDZ displacements allowed the progressive evolution of the fault systems to be evaluated. In cross-section, transtensional pull-aparts initiated as asymmetric grabens bounded by planar oblique-extensional faults. With increasing displacement on the PDZs, basin subsidence caused these faults to become concave-upwards and lower in dip angle due to fault block collapse towards the interior of the basin. In addition, strain partitioning caused fault slip to become either predominantly extensional or strike-slip. The models compare closely with the geometries of natural pull-apart basins including the southern Dead Sea fault system and the Vienna Basin, Austria. 相似文献
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Ship hulls, as well as bridges, port dock pilings, dams, and various underwater structures need to be inspected for periodic maintenance. Additionally, there is a critical need to provide protection against sabotage activities, and to establish effective countermeasures against illegal smuggling activities. Unmanned underwater vehicles are suitable platforms for the development of automated inspection systems, but require integration with appropriate sensor technologies. This paper describes a vision system for automated ship-hull inspection, based on computing the necessary information for positioning, navigation, and mapping of the hull from stereo images. Binocular cues are critical in resolving a number of complex visual artifacts that hamper monocular vision in shallow-water conditions. Furthermore, they simplify the estimation of vehicle pose and motion, which is fundamental for successful automatic operation. The system has been implemented on a commercial remotely operated vehicle (ROV), and tested in pool and dock tests. Results from various trials are presented to demonstrate the system capabilities 相似文献
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为提高我国海底掩埋目标的探查技术,以适应不断发展的探测需求,文章综述了现有三维合成孔径声呐在海底掩埋目标探查中的应用现状,并对关键技术的发展方向进行了展望。结果表明:尽管三维合成孔径声呐在海底掩埋目标探查中具有较大的技术优势,但是由于技术难度大、复杂程度高,可提供成熟商用设备的单位仅有两家,中科探海研发的三维合成孔径声呐系统多项核心技术指标领先。运动误差估计和补偿技术,掩埋目标特征提取和识别分类算法,多通道大规模数据并行处理算法等关键技术将成为三维合成孔径声呐系统未来的发展方向。 相似文献
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研究主要是以Visual studio 2005为开发平台,结合GIS组件和GPRS/CDMA宽带通讯技术进行农村环境监测系统二次开发。系统由水质自动监测系统、空气质量监测系统、噪音监测系统、和监测中心4部分组成。它具有样品自动采样、污染因子在线监测、农村污染源排放总量监测、数据自动传输和汇总分析等功能。 相似文献