绕跨声速三角翼的激波/涡干扰流场数值模拟

 在绕三角翼的跨声速流动中,随着迎角的增加,三角翼上的涡破裂位置会出现突然前移的现象。针对这一与亚声速下不同的流动现象,采用带曲率修正的Spalart-Allmaras(SAR)湍流模型,求解定常雷诺平均Navier-Stokes(RANS)方程,对不同迎角下绕65°后掠尖前缘三角翼的跨声速流动进行数值模拟,并在此基础上,采用基于SAR湍流模型的脱体涡模拟(DES)方法,对由激波干扰导致的前缘涡破裂位置的运动规律进行了初步探讨。模拟结果与试验结果对比表明:SAR湍流模型能准确地模拟出三角翼上的激波系统和旋涡结构,并能准确模拟出由于激波干扰导致的涡破裂位置突然前移的现象。此外,对涡破裂后流场的非定常数值研究发现,支架前端正激波的干扰作用使得涡破裂位置向下游移动比较突然,而向上游移动则相对缓慢。     

基于RELAX的空中多机动目标检测与参数估计

 针对机载雷达空中多机动目标的检测问题,提出了一种基于RELAX算法的空中多机动目标检测与参数估计方法。该方法将重构时间采样技术与RELAX算法相结合,有效地抑制了检测过程中强信号分量对弱信号分量的影响,在待测单元内存在多个目标时,能够获得很好的参数估计结果,并且在脉冲点数有限的情况下,该方法得到的参数估计精度依然很高。同时,本文还推导了空中多机动目标参数估值的克拉美罗界(CRB),为估计结果提供了理论下限。仿真结果证明了该方法的有效性。     

在役轰炸机改进改型的发展方向探讨

随着世界航空领域新技术、新设备、新材料的不断发展和应用，新型战略轰炸机不断创新发展的同时，现役战略轰炸机发挥价格优势，并不断改进提高，与新型飞机互为补充，可以最大限度地发挥出战略轰炸机整体的作战效能。借鉴国外现役战略轰炸机的改进改型，结合我国自身的国力、科技发展水平，提出换装功率更大、更节油的涡扇发动机；换装集成化更高，功能更先进，可靠性更高的机载设备；加装新研的机载设备提高攻击能力和自卫能力。     

探地雷达成像中多层介质分界面折射点确定

探地合成孔径（syngthetic aperture radar,SAR）雷达成像对于地下目标的检测与识别非常重要。地下多层介质时，各分界面上折射点确定对于探地合成孔径雷达成像非常关键。多层介质分界面上的折射点位置，目前尚无较好的确定方法。研究了两种确定多层介质分界面上折射点的方法，并讨论了所提出的一种简单有效的计算方法－“常量法”。该方法充分利用了电磁波在各层介质分界面上的折射特性，计算简单有效。     

美国空军未来的装备与技术——2010"技术地平线"报告分析

介绍了美国空军2010年发布的"技术地平线"的出台背景、主要内容.并根据该研究报告浅析了美国空军未来的装备与技术趋向.     

ASAR imaging for coastal upwelling in the Baltic Sea

Analysis of Envisat Advanced Synthetic Aperture Radar (ASAR) and Aqua/Terra Moderate Imaging Spectrometer (MODIS) infrared (IR) imagery of coastal upwelling in the southeastern Baltic Sea is presented. It is found that upwelling features are well distinct in the SAR images, and the leading imaging mechanism appears to be the change of the marine atmospheric boundary layer (MABL) stratification over the sea surface temperature (SST) front. This finding is supported by model calculations of the MABL transformation supplemented with the SAR backscatter calculations based on the CMOD4 model. In addition an empirical dependence of the SAR contrasts over the upwelling region on the wind speed and the SST drop is suggested. Finally, surface slicks accumulated in the sea surface current convergence zones generate additional distinct features in SAR imagery. This effect is interpreted within the framework of the coastal current circulation model based on analysis of the SST snapshot.     

TanDEM-X: A radar interferometer with two formation-flying satellites

TanDEM-X (TerraSAR-X add-on for Digital Elevation Measurements) is an innovative formation-flying radar mission that opens a new era in spaceborne radar remote sensing. The primary objective is the acquisition of a global digital elevation model (DEM) with unprecedented accuracy (12 m horizontal resolution and 2 m relative height accuracy). This goal is achieved by extending the TerraSAR-X synthetic aperture radar (SAR) mission by a second, TerraSAR-X like satellite (TDX) flying in close formation with TerraSAR-X (TSX). Both satellites form together a large single-pass SAR interferometer with the opportunity for flexible baseline selection. This enables the acquisition of highly accurate cross-track interferograms without the inherent accuracy limitations imposed by repeat-pass interferometry due to temporal decorrelation and atmospheric disturbances. Besides the primary goal of the mission, several secondary mission objectives based on along-track interferometry as well as new bistatic and multistatic SAR techniques have been defined, representing an important and innovative asset of the TanDEM-X mission. TanDEM-X is implemented in the framework of a public–private partnership between the German Aerospace Center (DLR) and EADS Astrium GmbH. The TanDEM-X satellite was successfully launched in June 2010 and the mission started its operational data acquisition in December 2010. This paper provides an overview of the TanDEM-X mission and summarizes its actual status and performance. Furthermore, results from several scientific radar experiments are presented that show the great potential of future formation-flying interferometric SAR missions to serve novel remote sensing applications.     

机载红外告警技术分析

机载红外告警技术是随着红外制导导弹对飞行平台日趋严重的威胁而发展起来的一种新型光电告警技术,对来袭导弹、战斗机或其他重要威胁源进行逼近告警,能有效提高飞机的战场生存能力,是飞机平台重要的防御设备.分析了机载红外告警系统的合理工作方式、技术指标需求与发展以及在研制过程中需攻克的关键技术,以期对机载红外告警系统的研制有一定借鉴作用.     

机载设备故障诊断方法的研究

针对某型系列飞机机载设备综合自动检测设备中故障诊断平台的研究,综合阐述了现有各种故障诊断方法的特点,并提出了研制中可能存在的问题和部分解决方案。     

蓝牙技术在某型飞机机载火控故障诊断系统中的应用研究

蓝牙是一种短距离无线通信技术,具有低成本、低功耗、灵活、快速、抗干扰能力强等特点,目的是取代终端的连接电缆.为提高部队的作战效能,采用蓝牙技术和计算机测量与控制技术,研制了机载火控故障诊断系统;该系统在实际应用中取得了良好效果,并具有诊断结果准确,自动化程度高,工作稳定可靠,操作简便,易于转移和维护等优点,为技术人员进行机载火控系统的性能检测与故障诊断提供了便利.