机载SAR运动目标的检测和成像处理

针对机载合成孔径雷达（ＳＡＲ），分析了运动目标的检测和成像处理的方法，通过对Ｗｉｇｎｅｒ－Ｖｉｌｌｅ分布（ＷＶＤ）同Ｗａｖｅｌｅｔ变换（ＭＴ）的分析和比较，将ＡＤＰＣＡ（ＡｄａｐｔｉｖｅＤｉｓｐｌａｐｈａｓｅＣｅｎｔｅｒＡｎｔｅｎｎａ）同ｗＴ相结合，从而达到对运动目标进行检测和成像的目的。对ＡＤＰＣＡ的对消比的计算机模拟，表明ＡＤＰＣＡ具有良好的杂波抑制能力。最后给出了可行的运动目标检测和成像的框图。     

数据融合技术在机载警戒雷达中的应用

介绍了机载警戒雷达主要计算机软件配置项及其功能,给出了机载警戒雷达软件控制与信息流程图,分析、比较了现有机载警戒雷达软件功能和JDL-USER数据融合模型功能.设计了融合处理软件架构,介绍了融合处理软件组成模块和功能需求,阐述了融合处理软件处理流程以及航迹融合流程与算法,实现了一次、二次雷达的航迹融合功能,还分析了数据融合技术在机载警戒雷达中的未来应用方向.     

机载雷达海面舰船目标ISAR成像技术研究

利用ISAR/SAR技术获得海面舰船目标的二维像是实现舰船目标分类识别的重要手段.文中研究了高海情条件下的机载雷达舰船目标ISAR成像方法,包括基于迭代相关的包络对齐、改进的"秩一"自聚焦相位补偿及利用"clean"技术的多分量调幅-调频信号参数估计的瞬时成像方法.实测数据成像结果证明了算法的可行性.     

Book Reviews

Books reviewed in this article: Grenoble, Leonore A. and Whaley, Lindsay J. (eds) Endangered Languages: Current Issues and Future Prospects van Dijk, Theun A (ed.) Discourse Studies: A Multidisciplinary Introduction. Volume 1: Discourse as Structure and Process. Volume 2: Discourse as Social Interaction Flowerdew, John The Final Years of British Hong Kong: The Discourse of Colonial Withdrawal gumperz, john j. and Levinson, Stephen C. (edds) Rethinking Linguistic Relativity Wodak, Ruth The Disorders of Discourse Clyne, Michael Undoing and Redoing Corpus Planning Bakker, Peter A Language of Our Own: The Genesis of Michif, the Mixed Cree-French Language of the Canadian Me´tis Ewers, Traute The Origin of American Black English: Be-Forms in the Hoodoo Texts Stevenson, Patraick The German Speaking World: A Practical Introduction to Sociolinguistic Issues Travers, Max The Reality of Law: Working and Talking in a Firm of Criminal Lawyers Gudykunst, William B., Ting-Toomey, Stella and Nishida, Tsukasa (eds) Communication in Personal Relationships Across Cultures     

湖南娄底方言中有特色的语气词举例

对湖南娄底方言中三组有特色的语气词共计12个进行较细致的描写和分析对比一、啊1、啊2、啊3、啊4、啊5.二、吧1、吧2、吧3.三、咧1、咧2、咧3、咧4.特点是每一组内的几个语气词,声、韵相同而声调不同,凭声调的不同区别语法作用.     

机载前向阵雷达近程杂波频移补偿

基于机载前向阵雷达在近距离地面目标检测时,杂波在距离上将呈现严重的非平稳性,提出了一种向量相似度准则,从杂波样本数据中计算补偿量的多普勒频移补偿方法。利用该方法对不同距离的杂波数据进行相应的频移变换预处理后,能有效改善近程地杂波的非平稳性。该算法在脉冲域和多普勒域中等效,适合并行运算,具有实现简单的优点。仿真结果表明经此方法预处理后的空时自适应滤波,能显著提高系统的性能改善因子。     

玻耳兹曼分布定律在经典物理化学中的应用

应用玻尔兹曼分布定律证明了范特霍夫渗透压公式、开尔文公式、胶体粒子沉降平衡公式等与粒子在外 力场中分布有关的基本公式,模型清晰,方法便捷.     

Validation of a Method for Estimating Long-Term Exposures Based on Short-Term Measurements

A method for estimating long-term exposures from short-term measurements is validated using data from a recent EPA study of exposure to fine particles. The method was developed a decade ago but long-term exposure data to validate it did not exist until recently. In this article, exposure data from repeated visits to 37 persons over 1 year (up to 28 measurements per person) are used to test the model. Both fine particle mass and elemental concentrations measured indoors, outdoors, and on the person are examined. To provide the most stringent test of the method, only two single-day distributions are randomly selected for each element to predict the long-term distributions. The precision of the method in estimating the long-term geometric mean and geometric standard deviation appears to be of the order of 10%, with no apparent bias. The precision in estimating the 99 th percentile ranges from 19% to 48%, again without obvious bias. The precision can be improved by selecting a number of pairs of single-day distributions instead of just one pair. Occasionally, the method fails to provide an estimate for the long-term distribution. In that case, a repeat of the random selection procedure can provide an estimate. Although the method assumes a log-normal distribution, most of the distributions tested failed the chi-square test for log-normality. Therefore, the method appears suitable for application to distributions that depart from log-normality.     

机载雷达杂波测量方法及其应用

雷达杂波是影响雷达性能发挥的重要因素,同时雷达杂波量化也是雷达性能验证评估的重要依据.在工程应用中,基于种种考虑,对试飞环境下的杂波测量需利用本机雷达来测量杂波.然而由于其非杂波测量专用雷达,也带来了一定的局限性和难度,在杂波测量方案中要统筹考虑.文中将结合机载雷达工程杂波测量,介绍雷达杂波测量的方法以及需要注意的问题,重点分析了杂波测量系统校准方法,并给出部分典型杂波测量和分析结果.     

波形综合机载雷达地杂波模拟方法性能分析

根据机载雷达地杂波的形成原理及其特点,提出了一种基于波形综合的机载雷达地杂波建模方法。该方法产生的地杂波可以控制杂波的时域幅度起伏和功率谱,在时域和频域同时具有与实际雷达地杂波相近的分布特性,从而可为机载雷达系统的测试提供可靠的数据来源。