排序方式: 共有55条查询结果,搜索用时 31 毫秒
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A cabled ocean observatory system that can provide abundant power and broad bandwidth communication for undersea instruments is developed. A 10 kV direct current (kVDC) with up to 10 kW power, along with 1 Gigabit/sec Ethernet communication, can be transmitted from the shore to the seafloor through an umbilical armored cable. A subsea junction box is fixed at a cable terminal, enabling the extension of up to nine connections. The box consists of three main pressure vessels that perform power conversion, power distribution, and real-time communication functions. A method of stacking modules is used to design the power conversion system in order to reduce the 10 kV voltage to levels that can power the attached instruments. A power distribution system and an Ethernet communication system are introduced to control the power supply and transmit data or commands between the terminals and the shore station, respectively. Specific validations of all sections were qualified in a laboratory environment prior to the sea trial. The ocean observatory system was then deployed at the coast of the East China Sea along with three in situ instruments for a 14-day test. The results show that this high voltage-powered observatory system is effective for subsea long-term and real-time observations. 相似文献
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This paper describes the implementation of a data logger for the real-time in-situ monitoring of hydrothermal systems.A compact mechanical structure ensures the security and reliability of data logger when used under deep sea.The data logger is a battery powered instrument,which can connect chemical sensors ( pH electrode,H2S electrode,H2 electrode) and temperature sensors.In order to achieve major energy savings,dynamic power management is implemented in hardware design and software design.The working current of the data logger in idle mode and active mode is 15 μA and 1.44 mA respectively,which greatly extends the working time of battery.The data logger has been successfully tested in the first Sino-American Cooperative Deep Submergence Project from August 13 to September 3,2005. 相似文献
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基于均值比率梯度增量符号相关原理,提出了一种SAR景象匹配算法。首先利用ROA梯度算子提取实时图和参考图的边缘梯度信息;然后引入增量符号对梯度信息进行二值化编码并实现相关分析;最后在多尺度影像分解的基础上完成由粗至精的逐层匹配。实验结果表明,该算法对噪声与梯度变化具有较强的鲁棒性,具有较高的正确匹配率和实时性。 相似文献
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引入影像重构的边缘检测算子性能评估方法 总被引:1,自引:0,他引:1
首先,利用待评估边缘检测算子进行边缘检测;然后,根据检测边缘支撑区融合边缘位置信息与灰度信息,并利用改进的灰度反距离分区加权均值法实现影像重构;最后,设计反映原始影像与重构影像之间特征相似度的性能评估综合指标,完成边缘检测算子的性能评估。实验结果表明,该评估方法的结论与人工判读的结果相吻合,并且不需要先验参考信息,有一定的工程应用性。 相似文献
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无线电高度表和数字地图的组合构成地形轮廓匹配 (TERCOM )辅助导航系统 ,它是一种飞行导航定位的重要手段 ,由于地形辅助导航不依赖卫星导航系统、不受外界干扰、具有自主导航的功能 ,故近年来获得了迅速发展。本文对传统的地形匹配算法进行了如下改进 :利用实测高程序列和预测高程序列与基准图分别进行匹配 ,对飞行器进行实时定位并对下一时刻的航迹进行预测 ;利用递推和分层匹配策略提高配准效率 ;利用多判据组合匹配提高定位的可靠性。根据本文所提出的数学模型 ,并用外场飞行数据进行了匹配测试 ,结果证明该方法提高了地形轮廓匹配的可靠性和精度 ,取得了很好的效果。 相似文献
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多源信息融合中小波变换的应用研究 总被引:12,自引:1,他引:12
研究了小波变换在多源信息融合中的应用,主要涉及高分辨率全色影像与低分辨率多光谱影像融合问题及合成孔径雷达与光学影像的融合问题.主要方法是基于地物光谱信息特征的彩色融合与基于几何特征的融合.利用小波技术对整个融合过程加以改进.获得的融合结果表明基于光谱特征信息的融合方法,可以有效地提高多光谱影像的空间分辨率,而基于几何特征的融合方法,可以提高对遥感影像的目视解译效果.视觉效果上就是将高分辨率影像的细节加入到了低分辨率多光谱影像中,并同时保持原始影像的光谱特征. 相似文献