对地观测卫星委员会(CEOS)介绍

随着全球人口的持续增加以及对资源压力的增大 ,我们必须了解地球系统——陆地、空气、水和生命的相互作用 ,了解人类如何影响这些系统 ,了解地球系统需要全球的努力。 1 984年 ,几个国家组成了对地观测卫星委员会 ( CEOS) ,协调国际所有民用卫星对地观测任务。这是一个政府机构间组织 ,到 2 0 0 1年初 ,已有40余个国家和国际空间组织参加 CEOS。CEOS被认为是对地观测卫星计划的主要协调组织 ,也是卫星计划与全球卫星数据用户对话的主要论坛。CEOS的网站为 :http://www/ceos.org。我国科技部中国国家遥感中心 ( NRSCC)和航天总公司…     

采用商业卫星构建虚拟星座

提出了虚拟星座的概念,从商业卫星资源优势、卫星参数差异和传感器特征差异3个方面分析了构建虚拟星座的可行性。以LANDSAT-7卫星和SPOT5卫星为试验对象,验证了构建虚拟星座的可操作性。     

星座卫星通信系统资源动态平衡模型的研究

资源动态平衡在星座卫星通信系统中具有重要的作用。针对目前星座卫星通信系统中影响资源平衡的因素,将宏观经济理论原理应用到资源平衡调配领域。从通信任务满足度出发,提出了基于虚拟工厂的资源动态平衡模型,详细阐述了模型中的3C评估指标体系,并以铱系统为例进行评估,验证了3C评估的可行性和有效性。通过模型的构建与求解,得出了星座卫星通信系统内、外部环境、用户需求及资源使用释放随时间推移和空间转换发生改变的关联关系,以及整个星座卫星通信系统达到帕累托最优的具体条件。资源动态平衡问题的研究,为解决星座卫星通信系统中的资源调配问题奠定了基础。     

国际卫星对地观测委员会（CEOS）18届全会、CEOS20周年庆典及国际对地观测技术与应用研讨会和展览会在北京隆重举行

11月16日，由中国科技部、国家航天局主办。国家遥感中心、中国空间技术研究院、中国科技交流中心和CEOS中国秘书处共同承办的CEOS18届全会、CEOS20周年庆典及国际对地观测技术与应用研讨会和展览会在北京中国国际贸易中心隆重开幕。世界各国负责对地观测的相关机构、国际科技组织的官员和专家学600余人汇集北京，共同交流全球对地观测技术及其应用的最新进展，     

基于多传感器洪水监测同化技术的初步研究

本文针对提高洪水监测的监测频率问题提出了多卫星多传感器洪水监测信息同化技术的研究。虚拟星座技术的出现与发展,为全球灾害监测系统的建立提供了支持,同时正逐渐应用到洪水监测中。本文基于虚拟星座技术提出多传感器专题信息同化概念,并对其技术路线和信息同化技术做了初步研究。     

刘闯、刘定生分别当选CEOS／WGISS用户副主席和技术与服务分组副主席

在2004年11月16～17日举行的第18届国际对地观测卫星委员会(CEOS)全会上，正式通过了信息系统与服务工作组(WGISS)主席、美国地质调查局数据中心John Faundeen博士提出的WGISS新一届领导层名单，其中包括中科院地理资源所全球变化信息研究中心主任刘闯研究员担任用户副主席，中科院遥感卫星地面站刘定生研究员担任WGISS技术与服务分组副主席，任期4年。     

嵌入式操作系统的发展趋势--CEOS

基于32位嵌入式微处理器的嵌入式操作系统正在从可用型、通用型到可定制型、优化型转变,该文阐述了可定制嵌入式操作系统（Customized Embedded Operating System,CEOS）是下一阶段嵌入式操作系统的发展趋势,综合论述了国内外可定制嵌入式操作系统CEOS的研究状况,提出了CEOS今后的研究方向,阐明了研究CEOS的意义。     

基于可靠性的5G-低轨星座网络切片映射算法

随着国家天地一体化信息网络重大项目的 推进,5G-低轨星座网络切片的可靠映射成为业内的研究热点.在基于软件定义网络(software-defined network,SDN)和网络功能虚拟化(network function virtualization,NFV)的5G-低轨星座集成网络架构下,将5G-低轨星座网络切片的可靠映射问题建模为一个混合整数线性规划问题.在此基础上,研究了切片请求的资源编排,进而提出了基于广度优先搜索的可靠映射算法.该算法综合考虑切片请求的可靠性阈值及虚拟网络功能(virtual network function,VNF)的资源需求,在虚拟网络映射中根据节点的可靠重要度对节点进行排序.仿真结果表明,该算法在满足可靠性阈值约束的条件下,能够最大化收益开销比,提高虚拟网络映射成功率,在切片可靠性及接受率等方面优于对比算法.     

基于现场观测数据的卫星雷达高度计海面风速和有效波高真实性检验方法研究

卫星遥感产品定量化应用前需通过真实性检验。卫星雷达高度计可观测海面风速大小和有效波高等海洋动力环境参数,而对其进行真实性检验存在不同的时空匹配方法。使用3种不同的时空匹配方法,利用美国国家浮标数据中心(NDBC)现场观测数据对2011年的Jason2海面风速和有效波高产品进行了检验。Jason2海面风速大小和有效波高的均方根误差分别为1.28 m/s和0.28 m,同时结果表明:采用卫星高度计海面风速大小(有效波高)和同步的现场观测数据在一定时间(1 h)和空间(50 km)限制条件下进行对比检验,可以得到合理的高度计海面风速大小和有效波高精度评价结果。 Jason2卫星高度计海面风速大小和有效波高的精度与探测海域有关,其精度在墨西哥湾与西大西洋海域相对较高。     

区域侦察小卫星星座设计与仿真

为满足全球观测需求,传统遥感卫星星座通常采用玫瑰星座或Ω星座,而此类星座无法满足对特定区域进行连续重复观测的需求,且星座本身无法完成观测信息的及时回传。针对上述问题,设计了利用MEO中继卫星的太阳同步回归轨道模型和共地面轨迹轨道模型。通过仿真分析两种轨道模型,发现同步太阳轨道星座可以提供独特的周期重复观察特性,但同样高度下的太阳同步轨道星座对特定区域连续覆盖性能远远低于共轨迹星座。研究证明了基于MEO中继卫星的共地面轨迹星座可以满足对地连续重复观测及实时回传信息的需求。     

Developments in the 'validation' of satellite sensor products for the study of the land surface

Increased availability of global satellite sensor data is resulting in an increase in satellite sensor products for global change research and environmental monitoring. The ensuing research and policy directives that will utilize these satellite products puts a high priority on providing statements of their accuracy. The process of quantifying the accuracy of these geophysical products is herein termed 'validation'. This Letter provides examples of international land product 'validation' research and describes a new international forum for coordination within the Committee on Earth Observation Satellites (CEOS) Calibration and Validation Working Group (CVWG).     

国际空间和对地观测技术发展战略新动向

对美国、俄罗斯、日本、加拿大等国以及国际对地观测组织和欧空局近期的空间和对地观测发展战略和计划进行了概要介绍和分析,包括美国对地观测组织近期的对地观测活动,NASA2007~2016年科学研究战略,俄罗斯2006~2015年对地观测卫星计划,日本的《JAXA 2025》,实现加拿大健康、安全和繁荣的联邦对地观测战略,国际对地观测组织2007~2009工作计划以及欧空局的生命行星计划面临新的科学挑战。对国际空间技术的发展动向进行了简要分析。     

Wildfire monitoring using satellite images,ontologies and linked geospatial data

Advances in remote sensing technologies have allowed us to send an ever-increasing number of satellites in orbit around Earth. As a result, Earth Observation data archives have been constantly increasing in size in the last few years, and have become a valuable source of data for many scientific and application domains. When Earth Observation data is coupled with other data sources many pioneering applications can be developed. In this paper we show how Earth Observation data, ontologies, and linked geospatial data can be combined for the development of a wildfire monitoring service that goes beyond applications currently deployed in various Earth Observation data centers. The service has been developed in the context of European project TELEIOS that faces the challenges of extracting knowledge from Earth Observation data head-on, capturing this knowledge by semantic annotation encoded using Earth Observation ontologies, and combining these annotations with linked geospatial data to allow the development of interesting applications.     

COSMO-SkyMed mission: risk management applications over China,Myanmar and Haiti conducted during 2008

Between 2007 and 2008, Agenzia Spaziale Italiana (ASI) and Ministero della Difesa (Italian Ministry of Defence) launched three out of the four X-band SAR (synthetic aperture radar) satellites of the Constellation of Small Satellites for Mediterranean Basin Observation (COSMO-SkyMed) dual-use (civilian and defence) mission, dedicated to Earth observation. The results received from the utilization of the two operative satellites of the constellation reveal the significant achievement of the X-band SAR sensor and the importance of a fast response time in risk management applications. This article presents the qualitative analyses and results related to a set of risk management applications of the year 2008 by ASI and e-GEOS pertaining to China, Myanmar and Haiti.     

Monitoring on-orbit calibration stability of the Terra MODIS and Landsat 7 ETM+ sensors using pseudo-invariant test sites

The ability to detect and quantify changes in the Earth's environment depends on sensors that can provide calibrated, consistent measurements of the Earth's surface features through time. A critical step in this process is to put image data from different sensors onto a common radiometric scale. This work focuses on monitoring the long-term on-orbit calibration stability of the Terra Moderate Resolution Imaging Spectroradiometer (MODIS) and the Landsat 7 (L7) Enhanced Thematic Mapper Plus (ETM+) sensors using the Committee on Earth Observation Satellites (CEOS) reference standard pseudo-invariant test sites (Libya 4, Mauritania 1/2, Algeria 3, Libya 1, and Algeria 5). These sites have been frequently used as radiometric targets because of their relatively stable surface conditions temporally. This study was performed using all cloud-free calibrated images from the Terra MODIS and the L7 ETM+ sensors, acquired from launch to December 2008. Homogeneous regions of interest (ROI) were selected in the calibrated images and the mean target statistics were derived from sensor measurements in terms of top-of-atmosphere (TOA) reflectance. For each band pair, a set of fitted coefficients (slope and offset) is provided to monitor the long-term stability over very stable pseudo-invariant test sites. The average percent differences in intercept from the long-term trends obtained from the ETM + TOA reflectance estimates relative to the MODIS for all the CEOS reference standard test sites range from 2.5% to 15%. This gives an estimate of the collective differences due to the Relative Spectral Response (RSR) characteristics of each sensor, bi-directional reflectance distribution function (BRDF), spectral signature of the ground target, and atmospheric composition. The lifetime TOA reflectance trends from both sensors over 10 years are extremely stable, changing by no more than 0.4% per year in its TOA reflectance over the CEOS reference standard test sites.     

世界主要国家对地观测技术发展策略

从对地观测技术计划入手, 对美国、欧空局、加拿大、日本、印度以及俄罗斯的对地观测技术发展现状和策略进行了概要的介绍和分析。美国EO S 计划的提出和实施带动了新一轮对地观测技术发展的浪潮, 而地球科学事业(ESE) 战略计划是对EO S 的提升与延续, 将地球系统科学的概念引入到计划中, 把对地观测技术与面临的科学问题紧密结合起来; 欧空局以遥感卫星1 号、2 号, 以及环境卫星而立足于世界对地观测技术前列, 法国以高分辨率SPO T 卫星系列、加拿大则以雷达卫星系列为其对地观测技术的特色发展策略。日本制定了未来对地观测基本策略, 并给出了未来卫星研制和发射计划日程; 俄罗斯作为空间大国, 在对地观测技术发展方面较为滞后, 近年来开始进行追赶; 发展中国家印度非常重视对地观测技术的发展, 随着其资源卫星的发射并稳定地提供数据,其对地观测技术发展引起世界广泛关注。     

Small satellite remote sensing and applications – history,current and future

The small satellite renaissance began in the 1980s and is changing the economics of space. Technological trends have supported the advancement of small satellites in the 1–500 kg range. The number of countries actively participating has grown substantially during the past years. Satellite constellations (groups of satellites working in concert) are emerging as a powerful and effective application. In this paper, we focus on the small satellites than can perform remote sensing or Earth observation tasks. An overview is presented of the small satellite literature on Earth observation. The aim of the survey is threefold: an introduction for those new to the field, an overview for those working in the field and a reference for those searching for literature on a specific application for Earth observation. Small satellite programmes are classified according to the geographic regions. The small satellite industry and small satellite systems are addressed. In terms of applications, small satellite constellations are discussed in more detail. Finally, future developments are put forward. Telegeoprocessing combined with grid computing will provide the infrastructure and technologies for the development of Processing on Demand for Small Satellite Constellation systems.     

Earth Observation application development based on the Grid oriented ESIP satellite image processing platform

Satellite images supply important information on earth surface, weather, clime, geographic areas, vegetation, and natural phenomena. Processing of satellite data requires high computation resources and flexible tools in order to search, discover, and reveal the main information, to experiment new algorithms, and to include them into new Earth Observation applications. This paper describes the features and the architectures of the ESIP and gProcess platforms, supporting the Grid based satellite imagery processing. The development methodology of Earth Observation applications is highlighted as well in order to hide the Grid complexity to the user.