我国陆地观测卫星现状及发展战略思考

本文回顾总结了我国陆地观测卫星载荷体系、地面系统建设及数据应用等方面的发展现状和成就,分析了当前所面临的挑战和任务,以此为基础,对我国陆地观测卫星的未来发展进行了战略思考和展望,提出了加强国家顶层规划、加强地面系统统筹建设、实现系列化业务化运营、加强国际合作、推进产业化发展等建议.     

Ecological assessment of Phragmites australis wetlands using multi-season SPOT-5 scenes

Ecologists and conservationists need accurate and replicable tools for monitoring wetland conditions in order to develop and implement adaptive management strategies efficiently. The Rhone Delta (Camargue) in southern France encloses 9200 ha of fragmented reed marshes actively managed for reed harvesting, waterfowl hunting or cattle grazing, and holding significant numbers of vulnerable European birds. We used multi-season SPOT-5 data in conjunction with ground survey to assess the predictive power of satellite imagery in modelling indicators of reed structure (height, diameter, density and cover of green/dry stems) relevant to ecosystem management and bird ecology. All indicators could be predicted accurately with a combination of bands (SWIR, NIR) and indices (SAVI, OSAVI, NDWI, DVI, DVW, MSI) issued from scenes of March, June, July, September or December and subtraction between these. All models were robust when validated with an independent set of satellite and field data. The high spatial resolution of SPOT-5 scenes (pixel of 10 × 10 m) permits the monitoring of detailed attributes characterizing the reed ecosystem across a large spatial extent, providing a scientifically-based, replicable tool for managers, stakeholders and decision-makers to follow wetland conditions in the short and long-term. Combined with models on the ecological requirements of vulnerable bird species, these tools can provide maps of potential species ranges at spatial extents that are relevant to ecosystem functioning and bird populations.     

基于卫星信号实现高精度时钟的设计

高精度时钟是通信网时间同步的基础,介绍了接收卫星导航定位系统的定时信号,校正本地晶振的输出,实现高精度时钟的设计方法。从高精度时钟的总体设计、硬件设计,针对硬件实现的关键技术展开阐述,按照ITU-T G．811标准的表征频率精确度和稳定度进行了测试,测试结果分析完全满足标准要求的指标。     

环境减灾卫星影像森林火灾监测技术方法研究

森林火灾是世界性的、频繁发生的重大自然灾害。随着国内外航天科技的迅猛发展,卫星遥感技术特别是红外卫星遥感已成为森林火灾监测的一种有效手段。我国的环境一号卫星A、B星(简称HJ-1A卫星、1B卫星)于2008年9月成功发射,其中的HJ-1B卫星搭载了红外多光谱相机,在森林火灾监测方面具有得天独厚的优势,可在早期的火灾发现、中期的灾害跟踪、后期的灾害损失评估中发挥重要作用。本文主要分析了环境减灾卫星在森林火灾监测方面的优势,对环境减灾卫星森林火灾监测技术和方法进行了研究。     

基于贪婪算法的卫星区域观测方案制定

针对卫星区域最优观测方案制定,将其抽象为集合覆盖问题和带附加条件的集合覆盖问题,在利用多星观测资源的情况下,提出了一种基于贪婪算法的解决方法,在该方法的基础上通过多次迭代求解来满足观测的实际需求。通过对该方法进行仿真实验,实验了不同条件下的求解情况,并对仿真结果进行了相关分析。     

稀土萃取过程组分含量的RBF软测量建模

稀土萃取分离过程的自动控制一直是稀土工业急待解决的关键难题,要实现稀土萃取分离过程的自动控制,首先必须解决串级萃取槽中各稀土组分含量的在线检测,而传统的检测又有很大的问题,软测量技术在稀土萃取过程控制中的应用研究开始活跃起来。该文是基于RBF网络的稀土萃取过程组分含量进行软测量建模的研究。     

Discharge properties and chemical stability of SrZrO films

Abstract— MgO thin film is currently used as a surface protective layer for dielectric materials because MgO has a high resistance during ion sputtering and exhibits effective secondary electron emission. The secondary‐electron‐emission coefficient γ of MgO is high for Ne ions; however, it is low for Xe ions. The Xe content of the discharge gas of PDPs needs to be raised in order to increase the luminous efficiency. Thus, the development of high‐γ materials replacing MgO is required. The discharge properties and chemical surface stability of SrO containing Zr (SrZrO) as the candidate high‐γ protective layer for noble PDPs have been characterized. SrZrO films have superior chemical stability, especially the resistance to carbonation because of the existence of a few adsorption sites due to their amorphous structure. The firing voltage is 60 V lower than that of MgO films for a discharge gas of Ne/Xe = 85/15 at 60 kPa.     

朱仙镇木版年画的“天地人合”

朱仙镇木版年画2006年被首批公布为中国非物质文化遗产,历史悠久,具有独特的地域艺术风貌,折射着浑厚的中原文化底蕴。农业文明向工业文明转型的中国,朱仙镇木版年画已经面临消亡的窘迫局面。本文在田野调查的基础上,结合相关的前学文献运用系统工程的方法以朱仙镇木版年画的传统工艺流程为切入点,对年画中的"天地人合"进行阐述,对朱仙镇木版年画相关文献的完善和保护具有拾遗补漏的意义。