中继卫星星间天线指向误差传播率研究

基于中继卫星星间天线对用户航天器的跟踪规律,建立了准确的误差传递模型,并对分析结果进行了仿真验证。文中首先定义了误差传递模型所需的各类坐标系;然后使用微分方法分别建立了中继卫星轨道误差传递模型、中继卫星姿态误差传递模型,分析了滚动角、俯仰角和偏航角与指向精度之间的关系,以及位置保持控制对指向精度的影响;最后借助于STK软件的轨道计算功能,使用蒙特卡罗方法进行数学仿真,仿真结果验证了误差传递模型的准确性。     

IP over CCSDS/AOS空间通信QoS保证方法

首先分析空间通信体系发展趋势,提出基于IP over CCSDS/AOS的空间通信模型。在分析总结了地面网QoS(服务质量)机制和AOS(高级在轨系统)虚拟信道调度机制的基础上,提出一种IP(互联网协议)网络层区分服务与数据链路层AOS虚拟信道动态调度相结合的QoS保证方法。该方法将网络层的业务等级划分映射到AOS的虚拟信道分配算法中,并在此基础上实现AOS虚拟信道的动态调度,提高包括话音、视频在内的综合业务在空间链路传输的性能。     

A multiple-rendezvous,sample-return mission to two near-Earth asteroids

We propose a dual-rendezvous mission, targeting near-Earth asteroids, including sample-return. The mission, Asteroid Sampling Mission (ASM), consists of two parts: (i) flyby and remote sensing of a Q-type asteroid, and (ii) sampling of a V-type asteroid. The targeted undifferentiated Q-type are found mainly in the near-Earth space, and to this date have not been the target of a space mission. We have chosen, for our sampling target, an asteroid from the basaltic class (V-type), as asteroids in this class exhibit spectral signatures that resemble those of the well-studied Howardite–Eucrite–Diogenite (HED) meteorite suite. With this mission, we expect to answer specific questions about the links between differentiated meteorites and asteroids, as well as gain further insight into the broader issues of early Solar System (SS) evolution and the formation of terrestrial planets. To achieve the mission, we designed a spacecraft with a dry mass of less than 3 tonnes that uses electric propulsion with a solar-electric power supply of 15 kW at 1 Astronomical Unit (AU). The mission includes a series of remote sensing instruments, envisages landing of the whole spacecraft on the sampling target, and employs an innovative sampling mechanism. Launch is foreseen to occur in 2018, as the designed timetable, and the mission would last about 10 years, bringing back a 150 g subsurface sample within a small re-entry capsule. This paper is a work presented at the 2008 Summer School Alpbach,“Sample return from the Moon, asteroids and comets” organized by the Aeronautics and Space Agency of the Austrian Research Promotion Agency. It is co-sponsored by ESA and the national space authorities of its Member and Co-operating States, with the support of the International Space Science Institute and Austrospace.     

北斗导航系统在物联网中的应用展望

物联网是信息技术领域又一个重要发展,它使传统网络从人与人的联系扩展到物与物、物与人的联系。北斗导航系统是我国正在建设的全球卫星导航系统。分析北斗导航系统在物联网中应用的可行性,从物联网的组成结构出发,分析北斗导航系统相比于传统电信网络的优势,并对北斗导航系统在物联网中的应用模式进行展望。     

Multi-GNSS contributions to differential code biases determination and regional ionospheric modeling in China

Due to the limited number and uneven distribution globally of Beidou Satellite System (BDS) stations, the contributions of BDS to global ionosphere modeling is still not significant. In order to give a more realistic evaluation of the ability for BDS in ionosphere monitoring and multi-GNSS contributions to the performance of Differential Code Biases (DCBs) determination and ionosphere modeling, we select 22 stations from Crustal Movement Observation Network of China (CMONOC) to assess the result of regional ionospheric model and DCBs estimates over China where the visible satellites and monitoring stations for BDS are comparable to those of GPS/GLONASS. Note that all the 22 stations can track the dual- and triple-frequency GPS, GLONASS, and BDS observations. In this study, seven solutions, i.e., GPS-only (G), GLONASS-only (R), BDS-only (C), GPS + BDS (GC), GPS + GLONASS (GR), GLONASS + BDS (RC), GPS + GLONASS + BDS (GRC), are used to test the regional ionosphere modeling over the experimental area. Moreover, the performances of them using single-frequency precise point positioning (SF-PPP) method are presented. The experimental results indicate that BDS has the same ionospheric monitoring capability as GPS and GLONASS. Meanwhile, multi-GNSS observations can significantly improve the accuracy of the regional ionospheric models compared with that of GPS-only or GLONASS-only or BDS-only, especially over the edge of the tested region which the accuracy of the model is improved by reducing the RMS of the maximum differences from 5–15 to 2–3 TECu. For satellite DCBs estimates of different systems, the accuracy of them can be improved significantly after combining different system observations, which is improved by reducing the STD of GPS satellite DCB from 0.243 to 0.213, 0.172, and 0.165 ns after adding R, C, and RC observations respectively, with an increment of about 12.3%, 29.4%, and 32.2%. The STD of GLONASS satellite DCB improved from 0.353 to 0.304, 0.271, and 0.243 ns after adding G, C, and GC observations, respectively. The STD of BDS satellite DCB reduced from 0.265 to 0.237, 0.237 and 0.229 ns with the addition of G, R and GR systems respectively, and increased by 10.6%, 10.4%, and 13.6%. From the experimental positioning result, it can be seen that the regional ionospheric models with multi-GNSS observations are better than that with a single satellite system model.     

PIS的概念和开发

结合航空制造业的一个实例，介绍了工艺信息管理系统的概念和开发策略，并对工艺信息系统的结构、功能及集成方法进行了分析，指出开发过程中出现的各种错误认识，以提高PIS开发的成功率。     

科研管理创新的必由之路——并行工程

讨论国有企业存在的弊病；介绍并行工程的定义、要素和结构；论述科研管理体制创新的必要性。研究表明，企业必须进行流程再造，改造成“学习型组织”，实现“能本管理“，在型号研制中采用“并行工程”。才能在激烈的市场竞争中立于不败之地。     

浅议高校贫困生资助的途径

目的 探讨完善高校贫困生资助的途径和办法。方法 在分析我国高等教育现阶段采用的多元化资助体系存在问题的基础上，提出解决问题的途径。结果 从政府、高校和贫困生三方面论述了应承担的责任：借鉴了美国多元化混合型大学生资助模式对我们解决问题的启示。结论 建立一套由政府主导，社会各界配合，高校具体实施的资助贫困生的长效机制是解决问题的根本。     

Initial design of laboratories for sustainable habitation

An effective and self-sustainable artificial habitat design is essential for human spaceflight and expansion of mankind into orbit or towards other celestial bodies. There are two approaches that need to be implemented in future sustainable habitats: the use of re-cycling technologies in order to gain experience in closed-loop processes and the primary production of resource materials using In Situ Resource Utilisation (ISRU) principles. Various products will be provided and, where applicable, recycled in such a system taking into account basic human factors requirements such as crew work load capacity, safety and well-being, namely:     

明确学报定位,实施特色战略--关于办好《西安航专学报》的思考

目的进一步明确高职高专学报的功能和定位，实现以特色和创新求发展的学报改革战略。方法在分析高职高专学报的功能和定位的基础上，结合西安航专学报近些年的改革发展历程，总结经验和存在的问题，明确学报进一步改革和发展的思路。结果从五个方面提出必须进一步提高质量意识；进一步强化创新意识。结论特色办刊、质量办刊和创新办刊是高职高专学报得以生存和发展的唯一出路。