共查询到20条相似文献,搜索用时 0 毫秒
1.
TDICCD相机的相对孔径与器件像元尺寸关系的研究 总被引:9,自引:1,他引:9
采用TDICCD可用小相对孔径光学系统 ,使相机轻型化。文章指出相机的相对孔径与TDICCD的像元尺寸必须正确地匹配 ,才能保证相机在奈奎斯特(Nyquist)频率处的实验室静态传递函数(MTFfN)≥0.2。确保相机装在卫星上飞行时 ,达到截止频率对应的地面像元分辨率 ,并介绍了国外TDICCD相机的主要参数。 相似文献
2.
航天遥感成像系统像元分辨率在轨检测方法研究 总被引:2,自引:0,他引:2
文章采用数学推导和图解模拟的方法,通过分析光电成像系统对三线靶标推扫成像的过程,说明使用三线靶标检验系统像元分辨率存在误差,可能得不出或得不到正确的结果,应使用辐射状靶标。 相似文献
3.
This paper presents the practice of the artist/researcher Ioannis Michaloudis. It showcases his use of a space technology nanomaterial, silica aerogel, and its potential in the cultural utilization of space. Since 2001, his projects have centered around the esthetic, sculptural and conceptual use of silica aerogel. For Michaloudis, this material is highly allegorical of what he terms ‘our breaking sky’. For the authors, the step towards space is a real ‘bridge moment’, analogous to the evolutionary progression of organisms from water to earth. In this current era of space exploration, it is clear that humans need to develop new organs and survival skills – or, cultivate new skies in response to the breaking of our atmosphere?s dome. It is also clear that science and art need to collaborate more productively. To this end, it is argued that allegory provides the link between imaginability, experiment and representation in both scientific and artistic practices. Etherospermia (εθεροσπερμ?α) is an invented word from ether and panspermia. The Etherospermia project pursues, allegorically, the creation of new atmospheres on other planets, in order to draw attention to the degradation and destruction of the earth?s protective veil. Imagine an astronaut who, during a space walk, scatters fragments of Michaloudis? silica aerogel as seed material to alter the atmospheres of other planets, making them habitable. The paper discusses nine artworks as a way of presenting the conceptual core of the etherospermia allegory. 相似文献
4.
《Space Policy》2014,30(4):202-208
I argue that the moral justification for space science is more compelling than the moral justification for space development. Thus, we ought to reemphasize the status of science as a major stakeholder in space, especially when entertaining policies which might encourage the kinds of space development activities (e.g. resource exploitation) that are liable to conflict with the scientific uses of space. 相似文献
5.
卫星应用在开发太空资源方面已取得丰硕成果,文中从卫星空间环境探测、卫星天文观察和卫星侦察监视三个角度论述了卫星在空间科学和军事侦察方面的应用。 相似文献
6.
CCD光斑质心算法的误差分析 总被引:1,自引:0,他引:1
文章建立了CCD噪声和像元尺寸对质心算法影响的误差模型.模型表明,当CCD上光斑的束腰ω<0.1个像元时,质心算法的误差大于0.28个像元;当束腰ω>0.5个像元时,像元尺寸对灰度质心算法的影响可忽略不计,影响质心算法的主要因素是CCD随机噪声误差.在ω>0.5个像元的前提下,光斑尺寸越小,质心算法的精度越高.实验与理... 相似文献
7.
8.
NASA's planned Ares V cargo launch vehicle offers the potential to completely change the paradigm of future space science mission architectures. Future space science telescopes desire increasingly larger telescope collecting aperture. But, current launch vehicle mass and volume constraints are a severe limit. The Ares V greatly relaxes these constraints. For example, while current launch vehicles have the ability to place a 4.5 m diameter payload with a mass of 9400 kg on to a Sun-Earth L2 transfer trajectory, the Ares V is projected to have the ability to place an 8.8 m diameter payload with a mass of approximately 60,000 kg on to the same trajectory, or 180,000 kg into Low Earth Orbit. Also the Ares V could place approximately 3000 kg (13,000 kg with a Centaur upper stage) on to a trajectory with a C3 of 106 km2/s2, arriving at Saturn in 6.1 years without the use of gravity assists. This paper summarizes the current planned Ares V payload launch capability. 相似文献
9.
地形起伏对星载SAR像素定位影响的仿真分析 总被引:4,自引:0,他引:4
通过点目标数据仿真,分析地形起伏变化对点目标方位向、距离向位置偏移的影响,并在此基础上,提出利 用斜距变化值和多普勒参数变化值对像素偏移值进行修正的方法,给SAR像素定位问题的研究提供了参考。 相似文献
10.
11.
12.
Planetary protection is NASA's term for the practice of protecting solar system bodies from Earth life while protecting Earth from life that may be brought back from other solar system bodies. Spacefaring nations will soon begin retrieving samples from Mars and other solar system bodies. For these samples, planetary protection is in order, and measures are already in place to prevent the forward contamination of Mars and other bodies by Earth microbes and the backward contamination of Earth by possible extraterrestrial life. A major goal of planetary protection controls on forward contamination is to preserve the planetary record of natural processes by preventing human-caused microbial introductions. 相似文献
13.
Space science missions are increasingly challenged today: in ambition, by increasingly sophisticated hypotheses tested; in development, by the increasing complexity of advanced technologies; in budgeting, by the decline of flagship-class mission opportunities; in management, by expectations for breakthrough science despite a risk-averse programmatic climate; and in planning, by increasing competition for scarce resources. How are the space-science missions of tomorrow being formulated? The paper describes the JPL Innovation Foundry, created in 2011, to respond to this evolving context. The Foundry integrates methods, tools, and experts that span the mission concept lifecycle. Grounded in JPL's heritage of missions, flight instruments, mission proposals, and concept innovation, the Foundry seeks to provide continuity of support and cost-effective, on-call access to the right domain experts at the right time, as science definition teams and Principal Investigators mature mission ideas from “cocktail napkin” to PDR. The Foundry blends JPL capabilities in proposal development and concurrent engineering, including Team X, with new approaches for open-ended concept exploration in earlier, cost-constrained phases, and with ongoing research and technology projects. It applies complexity and cost models, project-formulation lessons learned, and strategy analyses appropriate to each level of concept maturity. The Foundry is organizationally integrated with JPL formulation program offices; staffed by JPL's line organizations for engineering, science, and costing; and overseen by senior Laboratory leaders to assure experienced coordination and review. Incubation of each concept is tailored depending on its maturity and proposal history, and its highest-leverage modeling and analysis needs. 相似文献
14.
Li Chengzhi 《Space Policy》2011,27(3):157-164
Using the US-coined concept of space industrialization and reflecting the ongoing creation of a space economy, this paper maintains that China’s 20-odd years of practice and achievement in crop breeding in space should be seen as an integral part of any space economy. The paper analyzes the Chinese government’s space breeding policies, its support for it via financial allocation, and the relevant programs, and highlights the key achievements so far achieved in the sector. In conclusion, it outlines the main hurdles to crop breeding in space but looks forward to a bright future for this activity. 相似文献
15.
16.
This report summarises the presentations which took place at the ‘Space Traffic Control – Is the Space Debris Problem Solvable?’ conference hosted by the Royal Aeronautical Society on the 2nd July 2013. The conference sought to promote discussion over methods to deal with the issue of space debris in particular and speakers included representatives from the European Space Agency, the United Kingdom Space Agency, practitioners and academia. Themes which emerged during the conference included the urgency of the problem of space debris, the need for short-term and long-term solutions, the necessity for the development and implementation of space debris remediation technologies to complement existing mitigation efforts and, last but not least, the wider applications of space traffic control. Regarding the sub-title of the conference, ‘is the space debris problem solvable?’, it would appear from the presentations that while there is the potential for future management of the issue through debris remediation and harmonised mitigation efforts, no comprehensive solutions exist at the time of writing. 相似文献
17.
本文通过对《宇航学报》1981~1988年322篇论文中2466条参考文献的统计分析,得出以下结论,(a)宇航科学的文献情报源重在期刊类文献。(b)以《宇航学报》、《航空学报》、《AIAA,Jourual》等六种期刊类文献为重点文献。(c)中文的引文作者和论文作者相对集中。(d)期刊类文献的半衰期为8~10年。 相似文献
18.
空间科学不仅能够推动我国在基础科学研究领域取得重大科学突破,还能够有效牵引、带动航天高新技术的发展。中国科学院空间科学战略性先导科技专项是\"十二五\"时期我国空间科学领域最重要的系统性进展,开启了中国空间科学发展的新篇章。\"十三五\"时期,我国将继续研制、发射一系列新的空间科学卫星,这对航天运输系统提出了新的技术发展需求。发展空间科学必将推动我国的航天强国、世界科技强国建设进程。 相似文献
19.
为改善在空间站长期值守的航天员的业务生活,提出建立空间站网吧,为航天员提供因特网服务的构想。为此分析研究空间站空间因特网服务系统及其关键技术,提出空间站空间因特网服务系统构建方案。结合这一系统构建方案,一是研究解决了支持复杂异构网络运行的空间因特网网络协议设计技术,空间站空间因特网直接采用TCP/IP协议,并通过系统设计,较好地克服了TCP/IP协议不能适应空间通信链路的难题,支持采用基于TCP/IP协议的商用货架(COTS)软、硬件产品,可明显降低空间站空间因特网服务系统建设与维护成本;二是研究解决了涉及空间站测控通信网运行安全和空间信息安全的空间通信链路设计技术,空间站在同一条空间通信链路同时传输空间因特网数据和空间站测控通信数据,空间通信链路采用CCSDS的AOS协议,并通过建立虚拟的物理信道,解决了空间因特网数据和空间站测控通信数据的安全隔离问题,能满足空间站测控通信网运行安全和空间信息安全的要求。 相似文献
20.
空间环境对空间系统维修性设计的影响 总被引:2,自引:0,他引:2
从空间环境对在轨维修工作的影响以及空间系统故障的主要诱因2个方面,分析了空间环境对空间系统维修性设计的影响。研究表明,空间环境对在轨维修性的影响首先与维修安全有关;空间环境的恶劣条件既是航天器故障的主要诱因,又是在轨维修各种困难和限制的根源。 相似文献