RPC: The Rosetta Plasma Consortium

The Rosetta Plasma Consortium (RPC) will make in-situ measurements of the plasma environment of comet 67P/Churyumov-Gerasimenko. The consortium will provide the complementary data sets necessary for an understanding of the plasma processes in the inner coma, and the structure and evolution of the coma with the increasing cometary activity. Five sensors have been selected to achieve this: the Ion and Electron Sensor (IES), the Ion Composition Analyser (ICA), the Langmuir Probe (LAP), the Mutual Impedance Probe (MIP) and the Magnetometer (MAG). The sensors interface to the spacecraft through the Plasma Interface Unit (PIU). The consortium approach allows for scientific, technical and operational coordination, and makes optimum use of the available mass and power resources.     

某型航空发动机电子控制器转速通道自动测试系统

在研究某型航空发动机电子控制器转速通道工作原理的基础上，利用工控机组建了该控制器转速通道的自动检测系统。详细地介绍了控制器转速通道自动检测系统的设计过程，重点介绍了应用研华数据采集卡PCL-818L开发虚拟信号发生器的方法。     

NMD中导弹预警卫星系统的发展

介绍了美国国家导弹防御系统(NMD)的核心——导弹预警卫星系统自1959年以来的发展和未来趋势，详细阐述了国防支援计划(DSP)与天基红外预警卫星系统(SBIRS)的进展，并探讨了未来美国国家弹道导弹防御计划中导弹预警系统的组成和功能。     

遗传算法在软件测试数据生成中的应用

测试数据生成是软件测试中的关键环节,它的实现对于软件测试过程的自动化具有重要意义.本文阐述了用遗传算法作为核心搜索算法来生成软件结构测试数据的方法和技术,其中讨论了编码策略、评价函数构造及插装等问题的解决方案,并重点说明了如何对遗传算子进行改进,使算法在解决本问题时更加有效.实验数据证明该方法是高效的.     

Post-Newtonian tracking formulae to increase the shooting accuracy of autonomous LEO laser trackers

We introduce five post-Newtonian tracking formulae that would allow increasing the accuracy of the shooting systems on board autonomous LEO laser trackers. These formulae should be used when the current formulae cannot provide instants close enough to the optimal instants at which the trackers could safely shoot down unwished LEO middle-distant targets. In fact, they allow the trackers to produce not only the safest shooting actions, but also the most efficient ablations that might make the targets fall into the atmosphere for them to burn. The fact of the matter is in the falsifiability procedure introduced below, which allows to simulate sequences of unharming shooting actions with very narrow laser beams leading to identify the optimal pointing directions to previously selected debris objects whose size and composition are representative of these targets.     

单星无源探测弹道导弹射向估计新方法

天基预警系统是国家战略预警系统的重要组成部分,而单星探测预警是天基预警系统发展必经历程和重要环节,传统方法基于标准弹道模板先验信息支持,但标准弹道模板信息难以获取,无法实际应用.本文主要讨论在没有标准弹道模板先验信息支持的情况下,单颗预警卫星能否及早给出导弹射向估计的问题.通过建立弹道导弹飞行的动量模型和弹道平面切割模型,本文提出了基于单颗预警卫星观测视线对来袭导弹射向的估计算法,回答了单颗预警卫星观测情况下如何给出射向信息的问题,仿真计算结果表明,本文方法对于引导地基预警系统具有较高的精度和实用价值,本文方法亦可应用于各类单站无源探测(预警雷达,中低轨、大椭圆预警卫星等)的方位信息估计与空间目标机动的识别等问题.     

A novel target detection approach based on adaptive radar waveform design

To resolve problems of complicated clutter, fast-varying scenes, and low signal-clutterratio (SCR) in application of target detection on sea for space-based radar (SBR), a target detection approach based on adaptive waveform design is proposed in this paper. Firstly, complicated sea clutter is modeled as compound Gaussian process, and a target is modeled as some scatterers with Gaussian reflectivity. Secondly, every dwell duration of radar is divided into several sub-dwells. Regular linear frequency modulated pulses are transmitted at Sub-dwell 1, and the received signal at this sub-dwell is used to estimate clutter covariance matrices and pre-detection. Estimated matrices are updated at every following sub-dwell by multiple particle filtering to cope with fast-varying clutter scenes of SBR. Furthermore, waveform of every following sub-dwell is designed adaptively according to mean square optimization technique. Finally, principal component analysis and generalized likelihood ratio test is used for mitigation of colored interference and property of constant false alarm rate, respectively. Simulation results show that, considering configuration of SBR and condition of complicated clutter, 9 dB is reduced for SCR which reliable detection requires by this target detection approach. Therefore, the work in this paper can markedly improve radar detection performance for weak targets.     

航空发动机高能X射线测试系统

综合介绍了高能X射线测试系统在航空发动机试验中的作用和基本组成以及国内外高能X射线测试技术开发应用情况。     

Observational appearances of isolated stellar-mass black hole accretion – Theory and observations

General properties of accretion onto isolated stellar-mass black holes in the Galaxy are discussed. An analysis of plasma internal energy growth during the infall is performed. Adiabatic heating of collisionless accretion flow due to magnetic adiabatic invariant conservation is 25% more efficient than in the standard non-magnetized gas case. It is shown that magnetic field line reconnections in discrete current sheets lead to significant nonthermal electron component formation, which leads to a formation of a hard (UV, X-ray, up to gamma), highly variable spectral component in addition to the standard synchrotron optical component first derived by Shvartsman generated by thermal electrons in the magnetic field of the accretion flow. Properties of accretion flow emission variability are discussed. Observation results of two single black hole candidates – gravitational lens MACHO-1999-BLG-22 and radio-loud X-ray source with featureless optical spectrum J1942+10 – in optical band with high temporal resolution are presented and interpreted in the framework of the proposed model.     

Background limited infrared and submillimeter instruments

The temperature and emissivity of infrared and submillimeter telescopes are basic parameters that drive the optical and thermal design of astronomical space projects. They determine also, among other parameters, the self-emission of the instrument and the photon noise produced by this radiation on the detectors. By comparing the telescope brightness with that of the sky in the 1m–1 cm wavelength range, general conditions for background limited photometry are derived. For <0.4 mm, temperature is the driving parameter, and for >0.4 mm, temperature and emissivity have equivalent importances. It can be shown on actual projects that these two regimes determine different optical and thermal concepts. Although based on a simplistic approach, this work intends to help designers to handle some basic system parameters of infrared and submillimeter instruments.