超谱成像技术及其系统建模

超谱成像技术是未来图像情报（IMINT）系统的新兴技术。由于它能获得独特的空间和谱信息，目前正在快速地发展并被应用于国防、环境、陆地监测等许多军民应用领域。为了支持超谱传感器系统的设计和技术参数的折衷选择，美国林肯实验室开发了一种端对端分析模型，用以预测遥感系统的性能。该模型利用景象种类反射率的统计描述，并将之转换成大气、传感器和任何处理操作的影响量级。根据这些统计量的变换结果，就可获得系统的性能指标。该模型将遥感系统分为三个主要组成部分，即景象、传感器和处理算法。景象影响模型包括光照、大气能见度、阴影效应、临界效应和云层遮蔽。传感器影响模型包括辐射器噪声源，比如说耀斑噪声、热噪声、检测器读出噪声、量化噪声和相对校准误差等。处理部分则包括大气补色（校正）、各种线性变换以及用来获得检测概率的操作员数量。林肯实验室已经为几种成像光谱仪研制了相应的模型，其中包括机载超谱数字图像收集（HYDICE）设备，其工作波段覆盖0．4～2．5μm太阳光反射光谱区。本文给出这种模型的建模理论分析与操作，并提供了一个折衷选择技术参数的例子，用以表明这种模型对系统设计和传感器操作应用有着实际使用价值。

国外无人机发展趋势及关键技术

介绍了网络中心战(NCW)对无人机(UAV)的性能需求,归纳了当前国外无人机发展领域的热点和趋势,着重针对影响无人机关键性能的几大前沿技术的各自特点、研制现状及方向进行了分析和综述,并对其近期发展前景做出了预测,最后对国内无人机的相关研制工作提出了一些建议。

外军无人机当前技术发展重点及前景预测

现代战争对无人机的需求和依赖性日益增长,极大地驱动了该领域很多革命性的新概念的涌现。根据网络中心战的要求、围绕当前国外无人机研究领域的焦点,文章对其发展趋势做出了分析和归纳,指出:无人机的发展应顺应新的作战运用,集传感器、射手及通信结构为一身的高效费比、多任务平台将是无人机的下一个发展方向。为实现该目标,则必须大力发展包括传感器、数据链和信息处理等在内的关键技术,为无人机的性能提升提供必要的技术支撑。

Investigation on Physiological Status of Regional Vegetation Using Pushbroom Hyperspectral Imager Data

To extract vegetation pigment concentration and physiological status has been studied in two test areas covered with swamp and flourish vegetation using pushbroom hyperspectral imager (PHI) data which flied in September of 2000 at Daxing'anling district of Heilongjiang Province, China. The ratio analysis of reflectance spectra (RARS) indices, which were put forward by Chappelle et al (1992), are chosen in this paper owing to their effect and simpleness against both comparison with various methods and techniques for exploration of pigment concentration and characteristics of PHI data. The correlation coefficients between RARS indices and pigment concentration of vegetation were up to 0.8. The new RARS indices modes are established in the two test areas using both PHI data and spectra of different vegetations measured in the field. The indices' parameter images of chlorophyll a (Chl a), chlorophyll b (Chl b) and carotenoids (Cars) of the test areas covered with swamp and flourish vegetation are acquired by the new RARS indices modes. Furthermore, the regional concentration of Chl a and Chl b are extracted and quantified using regression equations between RARS indices and pigment concentrations, which were built by Blackburn (1998). The results showed the physiological status and variety clearly, and are in good agreement with the distribution of vegetation in the field.

机载传感器技术的新发展

为了完成搜索、跟踪、信号接收、干扰和通信等任务，美军正在着手研究将各种传感器信息通过网络进行连接和互补。