高精度紫外探测器定标测试方法

文章研究分析了紫外电学定标探测器的主要光电不等效因素,并建立了基于紫外电学定标探测器的紫外辐射定标系统。在此基础上,利用紫外探测器定标测试平台,开展了紫外探测器的测试方法研究,响应率定标的总不确定度为3%～5%,相对光谱测试的总不确定度为3%。     

Simultaneous observations of the plasma density on the same field line by the CPMN ground magnetometers and the Cluster satellites

By applying the cross-phase method and the amplitude-ratio method to magnetic field data obtained from two ground stations located close to each other, we can determine the frequency of the field line resonance (FLR), or the field line eigenfrequency, for the field line running through the midpoint of the two stations. From thus identified FLR frequency we can estimate the equatorial plasma mass density (ρ)$(\rho )$ by using the T05s magnetospheric field model [Tsyganenko, N.A., Sitnov, M.I. Modeling the dynamics of the inner magnetosphere during strong geomagnetic storms, J. Geophys. Res. 110, A03208, 2005] and the equation of Singer et al. [Singer, H.J., Southwood, D.J., Walker, R.J., Kivelson, M.G. Alfven wave resonances in a realistic magnetospheric magnetic field geometry, J. Geophys. Res. 86 (A6) 4589–4596, 1981].     

Qualitative estimation of magnetic storm efficiency in producing relativistic electron flux in the Earth’s outer radiation belt using geomagnetic pulsations data

It is well known that during many but not all of the geomagnetic storms enhanced fluxes of high-energy electrons are observed in the outer radiation belt. Here we examine relativistic (>2 MeV) electron fluxes measured by GOES at the synchronous orbit and on-ground observations of two types of ULF pulsations during 30 magnetic storms occurred during 1996–2000. To characterize the effectiveness of the chosen magnetic storms in producing relativistic electron fluxes, following to (Reeves, G.D., McAdams, K.L., Friedel, R.H.W., O’Brien, T.R. Acceleration and loss of relativistic electrons during geomagnetic storms. Geophys. Res. Lett. 30, doi:10.1029/2002GL016513, 2003), we calculate a ratio of the maximum daily-averaged electron flux measured during the recovery phase, to the mean pre-storm electron flux. A storm is considered an effective one if its ratio exceeds 2. We compare behavior of Pi1 and Pc5 geomagnetic pulsations during effective and non-effective storms and find a tendency for a storm efficiency to be higher when the mid-latitude Pi1 pulsations are observed for a long time during the magnetic storm main phase. We note also that the prolonged powerful Pc5 pulsation activity during the recovery phase of a magnetic storm is the necessary condition for the storm effectiveness. To interpret the found dependences, we suggest that there are two prerequisites for generating relativistic electron populations during a storm: (1) the availability of seed electrons in the magnetosphere, and Pi1 emissions are indicators of the mid-energy electron interaction with the ionosphere and (2) acceleration of the seed electrons to MeV energies, and interaction of electrons with the MHD wave activity in the Pc5 range is one of the most probable mechanisms proposed in the literature for this purpose.     

Study on solar sources and polar cap absorption events recorded in Antarctica

Particularly intense events occurred on the Sun in a period around minimum of solar activity during cycle 23. We investigated the characteristics of September 2005 and December 2006 events and the properties of the correlated observations of ionospheric absorption, obtained by a 30 MHz riometer installed at Mario Zucchelli Station (MZS-Antarctica), and of geomagnetic activity recorded at Scott Base (Antarctica). Solar events are studied using the characteristics of CMEs measured with SoHO/LASCO coronagraphs and the temporal evolution of solar energetic protons in different energy ranges measured by GOES 11 spacecraft.     

OpenGL在红外辐射计算中的应用

提出一种将OpenGL应用在目标红外辐射特性计算中,从而实现目标红外辐射特性可视化计算的方法.由于OpenGL可用于构造三维模型,进行三维图形交互软件的开发;因而将其引入红外辐射特性计算中可解决复杂目标计算问题,而且图形硬件的消隐能力避免了遮挡计算并使计算以所见即所得的方式实现可视化.针对目标红外辐射特性中的自身辐射和目标对太阳光的反射部分,分别运用光照模型中发射光和漫反射的特性,以像素的颜色获取温度参数和法矢从而实现可视化计算.用一个简单标准体模型进行验证,计算结果表明了该方法的有效性和可行性.     

TiO2光催化薄膜在空间污染防护 应用中的探索

文章采用溶胶凝胶法在JGS1石英玻璃上制备了TiO₂薄膜,并对其晶体结构与光催化性能之间的关系进行了研究,探讨了紫外光辐照下TiO₂薄膜对大分子链硅油光催化效果。结果表明:经500 ℃热处理后的TiO₂薄膜为锐钛矿结构,具有较高的光催化活性;在253 nm紫外光辐照下,TiO₂薄膜对大分子链硅油表现出较好的光催化降解效果。该研究将为空间环境下飞行器光学表面污染净化材料的开发提供有益参考。     

卫星用光纤陀螺三轴组合的关键技术

研究了空间环境对光纤陀螺各项指标的影响,设计了一种新颖的卫星用光纤陀螺三轴组合.针对空间辐射、温度循环和真空环境对光纤陀螺的影响进行了模拟实验,通过分析实验数据得到了空间环境对光纤陀螺主要参数的影响机理.利用最小二乘滤波的方法建立了偏置误差模型,利用查表法建立了标度因数误差模型,并用现场可编程门阵列(FPGA)实时进行零偏和标度因数补偿,补偿后陀螺输出零偏稳定性为0.1(°)/h.同时详细分析了陀螺在空间低角速度环境下产生死区的原因,并利用周期相位扰动调制的方法消除了死区.在卫星用光纤陀螺三轴组合的设计中,实现了光源复用和冗余、空间主动和被动防护措施、在轨故障诊断等技术.      

太阳辐射对环火段通信链路的影响分析及参数设计

深空探测的上合阶段(superior solar conjunction,SSC),太阳强辐射成为影响地面站接收噪声温度计算分析的关键性因素之一。针对太阳辐射引起的高传输误码率甚至通信中断问题,以火星探测为例,提出一种定量化计算环火段太阳 地面站 探测器夹角∠SEP的方法,结合角度关系分析了环火段SSC阶段太阳对链路产生影响的原因,重点分析了地面站接收太阳噪声温度与空间链路、空口参数以及天线波束特性之间的关系。研究及仿真试验表明,当天线口径一定时,地面站的接收噪温峰值Tsmax和太阳对地面站的影响时长ti均与通信频率成反比; 在通信频率一定时,Tsmax与天线口径成正比,t_i与天线口径成反比;当天线口径固定为34m时,S频段下的Tsmax高达12830K,是Ka频段下的1.8倍,S频段的ti比Ka频段下的ti表现在∠SEP上延长近0.5°。当通信频率固定为S频段时,70m口径天线与18m口径天线相比,Tsmax高出1920K,但是ti表现在∠SEP上缩短约0.53°。结合太阳辐射对通信链路的影响分析,给出了不同∠SEP下的链路参数设计建议,为火星探测链路中的参数设置提供参考。     

扇面波导斜缝特性的矩量法分析

根据缝隙口面切向场的连续条件,采用解析数值法--矩量法,对扇面波导宽壁上窄的斜缝进行了计算,解得了磁流系数及其分布,并得到散射场、等效散射参量及等效阻抗等重要参数.假定波导中仅有TE-11主模传输,在X波段计算了散射参量和归一化等效串联阻抗,给出计算结果,为缝隙天线和缝隙阵列设计提供了依据.     

热管式平面热辐射源

本文所述热管式平面热辐射源,用于扫描辐射计、分光计和热像仪等遥感仪器的分度、定标。测试结果表明,热管式平面热辐射源的工作面等温性比传统设备更好。这种设备还具有无振动、无噪声、不污染环境等优点。