Precursor to an African Space Agency: Commentary on Dr Peter Martinez “Is there a need for an African Space Agency?”

In 2012 a working group was established to formulate the African space policy and strategy which would lead to the establishment of an African Space Agency (ASA). Dr Peter Martinez asserts in his article “Is there a need for an African Space Agency?” [1] that the arguments that have been posited in support of an ASA are flawed; namely the arguments of the existing example of the European Space Agency (ESA), and that an ASA would lead to fostering competition, synergy, industrial development and capacity building. While this viewpoint agrees that all the perfect conditions may not exist at present for the creation of an ASA, it addresses some of the issues raised by Martinez, and proposes ideas to foster intra-regional cooperation.     

空间信息对抗能力与技术需求

在陆、海、空、天、电战争范畴,空间攻防对抗是战略制高点。从美军的空间对抗的发展和变化,折射出未来的空间对抗需求已由“确保摧毁”向“确保生存”的战略概念转变,由“硬杀伤”向“软能力”倾斜。从需求出发,提出未来空间信息对抗能力设想,以及实现这些能力的主要关键技术。     

Kinetic Excitation Mechanisms for ION-Cyclotron Kinetic Alfvén Waves in Sun-Earth ConnectionI

We study kinetic excitation mechanisms for high-frequency dispersive Alfvén waves in the solar corona, solar wind, and Earth's magnetosphere. The ion-cyclotron and Cherenkov kinetic effects are important for these waves which we call the ion-cyclotron kinetic Alfvén waves (ICKAWs). Ion beams, anisotropic particles distributions and currents provide free energy for the excitation of ICKAWs in space plasmas. As particular examples we consider ICKAW instabilities in the coronal magnetic reconnection events, in the fast solar wind, and in the Earth's magnetopause. Energy conversion and transport initiated by ICKAW instabilities is significant for the whole dynamics of Sun-Earth connection chain, and observations of ICKAW activity could provide a diagnostic/predictive tool in the space environment research. This revised version was published online in August 2006 with corrections to the Cover Date.     

空间群Pn3mPn3P23子群链耦合系数的计算

本文利用陈金全教授的本征函数法计算了Pn3m Pn3 P2 3空间群的母分系数。最后的计算结果表明 ,用陈金全教授的本征函数法所求得的母分系数确实满足幺正、归一性 ,同时也证明了本征函数法对于求母分系数同样适用     

The land remote sensing commercialization Act of 1984

This article examines the effect that private-sector remote sensing activities might have on the international community and on the future of international cooperation in space. It describes in detail The Land Remote Sensing Commercialization Act of 1984, recently passed by the US Congress and signed by President Reagan. The article concludes that it is possible to develop domestic regulations that balance the economic interests of the private sector with the legal and political concerns of the international community.     

高分影像辅助下的航空高光谱严密几何检校方法

 惯性测量单元(IMU)与传感器视准轴的偏心角和偏心矢量是造成航空线阵列高光谱数据几何校正误差的主要原因之一。在分析偏心角与偏心矢量误差来源之后提出该误差由IMU主轴与传感器主轴的角度偏差、测区固定偏差、GPS中心与传感器投影中心相对偏差组成,在此基础上建立了较为严密的检校模型。针对模型解算时需要大量高精度控制点的问题,提出了一种高分影像辅助下的亚像元精度控制点自动提取方法。通过多地区、多传感器高光谱航测实验表明,亚像元精度控制点能有效提高模型解算精度。新检校模型可获得亚像元校正精度,推扫式传感器——应用型机载成像光谱仪(AISA)建模中误差约为0.39个像元,摆扫式传感器——实用型模块化成像光谱仪(OMIS)建模中误差约为0.23个像元,校正后的影像可直接进行拼接。     

基于连续同伦算法的天基仅测角初定轨方法

要进一步提高天基短弧初定轨的精度,在观测资料精度较高的情况下,仅考虑二体问题是不够的,还应考虑轨道摄动的影响。因此,基于无摄初轨的单位矢量法原理和矢量斜分解方法,给出了考虑摄动的天基仅测角初定轨单位矢量法。针对天基仅测角观测条件方程组求解过程中易出现迭代不收敛或收敛到平凡解的问题,引入连续同伦算法求解观测条件方程组,提出了单星观测方式下的空间目标天基仅测角初定轨方法,并通过数值仿真算例验证了该算法在较大范围的收敛性和数值稳定性。     

电子设备整机三维布线工艺研究

为了提高电子设备整机布线的质量和效率,提出了一种基于电子设备三维结构模型的整机三维布线工艺技术。分析了三维布线技术在设计阶段和生产加工阶段的优势,给出整机三维布线设计流程,对其中涉及的关键技术——空间布线技术和三维布线工程图进行了重点分析,并以某型无人机机载电子设备布线设计为例,验证了三维布线关键技术在产品研制中能够起到优化设计、简化流程、提高布线精度、保障质量的作用。     

时域有限体积法的格式稳定性分析

以模型方程为例,采用MUSCL插值的S-W通量分裂格式,分别结合二步、四步龙格一库塔时间推进格式建立数值求解方法.用Von Neumann傅里叶级数分析方法,通过对不同格式的放大因子及色散因子的计算,分析了时域有限体积法(FVTD)格式的稳定性.     

End-to-End Modeling of the Solar Terrestrial System

Traditionally modeling for space science has concentrated on developing simulations for individual components of the solar terrestrial system. In reality these regions are coupled together. This coupling can be as simple as the driving of the magnetosphere – ionosphere – thermosphere system by the solar wind or as a complicated as the feedback of the ionospheric conductivity and currents on the magnetosphere. As part of the CISM project we are beginning a concentrated effort to compressively model the entire system. This approach includes chains of models. In the first chain physics based numerical models are utilized while in the second chain empirical models are coupled together. The first half of this paper discusses the numerical modeling approach by highlighting the coupling of pairs of regions within the system. In the second section we present results from empirical models which are combined to make long term forecasts of conditions in the geospace environment. It is expected that a validated and reliable forecast model for space weather can be obtained by combining the strongest elements of each chain.