Simulation and evaluation of the quality and availability of typical GLI ocean image

ADEOS-II satellite will be launched in the near future. It collocates many remote sensing instruments in the same platform. Among them, Global Image (GLI) is considered to be a main sensor which will play a key role. In order to understand the characteristics of future GLI ocean color images, a simulation and evaluation of the quality and availability of GLI typical ocean image has been done. In the paper, we first introduce the simulation models briefly, and simulate typical cases of radiance images at visible channels, in which the radiance distribution is based on geographic location, the satellite orbital parameters and sensor properties. A method, complex signal noise ratio (CSNR) to evaluate the image quality and availability, is developed according to the characteristics of image. Meanwhile, a series of CSNR images are generated from the simulated radiance components for different cases, which can be used to evaluate the quality and availability of GLI images before the ADEOS-II is placed in orbit. Finally, the quality and availability of GLI images are quantitatively analyzed by the simulated CSNR data. The results will be beneficial to the people who are in charge of GLI mission or plan to use the data from GLI.     

电场辅助K+-Na+交换玻璃光波导的制作与优化

在激光玻璃中使用电场辅助K+ Na+离子交换法制作了平板光波导,发现实验结果与以往电压-时间乘积经验公式计算结果之间存在较大误差.不能忽略空间电荷分布产生内电场效应的影响,并将以往经验公式中的辅加电压项用辅加电压与玻璃内电场之差代替,使用改进后的理论模型计算的不同辅加电压范围和交换时间下的光波导扩散深度与实验数据一致.     

标量FDTD法分析渐变折射率光波导模场分布

用标量时域有限差分法（Finite-differece Time-domain Method,FDTD法）分析了渐变折射率平面光波导中基模的模场分布情况，采用平面光波、球面光波、高斯光波等5种不同形态的光波激励同一波导，借助计算机进行数值求解，得到的光场分布图在光场传播达到稳定后完全相同，说明波导的模式与光波形态无关，只与波导结构和光波波长有关，结果表明该方法直观、精确、快速，并与解析法分析的结果一致。     

东海北部近海夏秋季鲐鲹渔场与海洋水文环境的关系

本文叙述了东海北部近海夏秋季鲐鲹鱼中心渔场的分布、海洋水文环境(包括水温、盐度、水系的消长变化)特点以及两者之间的关系。     

铁路沿线山岬对电波传播特性影响分析

利用波导分析理论及介质表面阻抗的概念,分析了电波在非理想表面的山岬中的传播特性．同时,对频率为９００ ＭＨｚ 的电波在非理想表面的矩形山岬内的传播特性进行了理论计算与分析．计算分析结果表明,环境媒质的相对介电常数对电波传播特性的影响较其它环境参数对电波传播特性的影响要明显得多．非理想表面介质增加了电波传播能量的损耗,缩短了纵向传播距离．在传播的横截面上,水平方向的电场衰减呈现波动分布．     

Design of continuous long slot leaky-wave antenna for millimeter wave application

A simple and efficient design scheme of the continuous long slot leaky-wave antenna is developed. The key steps involved in the scheme are summarized. First, the cut-off frequencies of slot waveguides with different slot offsets are obtained by 3D finite-difference time-domain (FDTD) method. Second, the attenuation function αra is estimated by the aperture distribution, and the attenuation function αrs is determined by the slot radiation.Finally, the attenuation function αra is combined with the attenuation function αrs by the coefficient K. And an example in Ka band is presented. Moreover, the return loss of the E-plane Tee-junction (ET) and the radiation pattern of leaky-wave antenna are simulated. The scheme is verified by comparing with the experimental result.     

我国海洋主题公园的发展阶段及其特征

通过网络、书籍、学术期刊及实地考察等渠道,共搜集了55家海洋主题公园的详细资料进行分析,从中获得了国内海洋主题公园发展的总体概况;对国内海洋主题公园的发展历程进行回顾,归纳并阐述了其不同发展阶段所表现出的主要特征,总结了海洋主题公园发展的生命周期规律及经验教训,以期为已经运营或拟建的海洋主题公园提供借鉴.     

二维方柱光子晶体的波导特性

具有缺陷的光子晶体,光子频率带隙内将出现局域模,而线缺陷相应地形成一个传输效率很高的光波导.计算了空气中Al材料的旋转四边形直柱光子晶体存在线缺陷时的带结构和态密度,给出了二维方形光子晶体的波导的TM模的电场分布,并讨论了波导耦合的传输效率.     

缓坡上波浪谱在流作用下的变形

本文将波浪作用通量守恒原则应用于缓坡上在水流作用下的波谱变形，并与规则 波的计算结果作对比。文中比较了采用不同的海浪谱的变形情况，同时还分析了波浪 能量方向分布对缓坡上在水流作用下波谱浅水变形的影响。     

基于EM算法的水下目标辐射噪声模型参数估计

对水下目标辐射噪声的混合高斯模型进行参数估计时,针对极大似然函数很难求解的问题,研究了一种使用海洋环境噪声统计信息的期望值最大算法(EM算法).在对Bouvet和Schwartz水下目标辐射噪声信号和海洋环境噪声模型研究的基础上,修正了传统的EM统计算法,以降低计算的复杂度,提高迭代收敛速度.仿真结果和实船信号实验数据的一致性,表明基于EM算法的混合模型参数估计方法,使得参数估计复杂度降低,运算量明显减少,估计性能较好,具有很好的应用价值.