合成孔径雷达数据减灾应用潜力研究综述

合成孔径雷达SAR(Synthetic Aperture Radar)技术是一种主动的对地观测技术,已在国内外减灾领域得到了广泛的应用。环境减灾HJ-1C SAR卫星是我国第一颗民用SAR卫星,也是我国第一颗用于减灾救灾领域的SAR卫星,已于2012年11月19日发射成功。在HJ\|1C SAR卫星发射前,从SAR技术特点出发,分别分析了单极化、多极化、干涉、极化干涉SAR数据在灾害预警监测评估领域的应用现状及潜力。对于推动利用SAR技术进行灾害监测预警业务体系向更深层面发展,推动高级空间技术在减灾领域的应用,以及推动我国在灾害监测预警领域的SAR卫星星座的建设具有重要意义。     

遥感卫星灾害应急监测效能评估指标体系构建

遥感卫星广泛应用于包括防灾减灾在内的多个领域,发挥了巨大的社会效益。自然灾害应急对卫星监测的需求具有针对多时空要素的动态高效多源多维的特点,而卫星的全球化可重访、无国界观测能力与灾害的监测需求高度契合。在研究分析遥感卫星在灾害应急任务中的能力需求和应用模式的基础上,从单项性能、能力指标和应用效能三个层次展开分析,构建遥感卫星灾害应急监测效能评估指标体系,给出主要指标的评估方法,为我国卫星有效用于国内外重大灾害应急监测服务提供有效的评估手段和技术支撑。     

遥感技术在减灾救灾中的应用

遥感技术已经广泛应用于地震、洪涝、台风等自然灾害的减灾救灾工作中,并在灾前预警准备、灾中监测救援和灾后评估恢复阶段发挥了重要的作用。首先介绍了灾害信息获取中常用的可见光、热红外和雷达数据及其特点,然后分析了遥感技术在减灾救灾中的应用优势,并对其在灾害不同阶段的作用进行了讨论。最后结合遥感的特点和数据处理方法,介绍了遥感在不同种类灾害中的应用情况,并对我国遥感技术在减灾救灾应用中的发展方向进行了展望。     

基于SSH框架和DWR技术的减灾卫星运行管理系统建设

根据卫星遥感在灾害监测与救灾减灾中的应用特点,研究了减灾应用中卫星数据申请、生产的规范和流程,并根据规范和流程,利用SSH和DWR框架实现了一个减灾卫星运行管理系统.在该系统中,利用SSH框架实现了MVC软件设计模式中M模型层、V表示层、C控制层的分离,降低了系统的耦合度,并利用Spring的面向切面编程(AOP)特性,实现了系统中的数据库事务和日志模块,降低了系统的开发难度.运行结果表明,该系统采用DWR框架实现了AJAX,减少了页面的刷新次数,改善了显示效果,提高了用户的体验度.     

基于三级并行的遥感业务化处理系统研究

分析了遥感业务化处理系统的现实需求,针对当前遥感业务化处理系统存在的不足,结合遥感业务化处理系统和遥感影像并行处理算法两方面研究的成果,提出了基于三级并行的遥感业务化处理系统设计方案,将数据并行、功能并行、任务并行融合到遥感业务化系统中,并在环境与灾害监测预报小卫星星座系统工程中得到应用,为环境减灾提供了快速的遥感处理支持。介绍了系统的体系结构,工作流程,重点研究了三级并行的实现方式,并借助产品实例对其性能进行了测试。结果表明,基于三级并行的遥感业务化处理系统设计方案能够有效的提高遥感业务化处理的效率。     

中国卫星减灾系统的方案设想

设想中的减灾系统由两部分组成:①自然灾害空间监测系统;②自然灾害信息地面应用系统。空间监测系统包括:风云一号极轨气象卫里(FY-1)、风云二号静止轨道气象卫星(FY-2)、资源一号(ZY-1)资源探测卫里和“减灾卫星”。前三颗卫里已发射或将要发射,“减灾卫星”正在设想之中,其将通过合成孔径雷达、10     

提高天气预报准确度 风云三号卫星作用重大

在风云三号卫星发射成功并顺利传回第一轨可见光图像后,中国气象局相关负责人在接受本报记者采访时指出,风云三号卫星不仅是奥运卫星,更是防灾减灾卫星。该卫星将为现代气象事业的发展,特别是提高天气预报和气候预测准确度发挥更加重要的作用。这位负责人介绍说,风云三号卫星是我国“十一五”期间投资规模最大、系统最复杂、有效载荷最多、应用系统最复杂、国内应用面最广、国际影响最大的一颗民用卫星,将为我国防灾减灾发挥重要作用,还将为国民经济可持续发展,乃至构建人与自然和谐相处的新型社会发挥非常重要的作用。他举例说,在防灾减灾方面,从长期平均来看,我国每年70%以上的灾害是气象灾害及气象衍生灾害。因此气象服务保障对防     

救灾中的信息化

近年来我国自然灾害应急管理体系建设、综合减灾能力建设和中国特色社会主义所具有的政治优势、组织优势、群众优势,在历次抗灾救灾工作中发挥了重要的基础性作用。在灾害预警方面,我国也进一步加强了灾害监测和预警预报系统建设,综合运用多种科技手段提高灾害监测预警预报能力,及时向各级政府部门、企事业单位和社会公众发布信息,服务和指导各项防灾备灾工作。同时,我国政府和各界也深刻认识到,当前仍迫切需要提升减灾防灾救灾水平,尽可能减少自然灾害带来的损失。在这其中,值得关注的是,信息化已成为监测分析预警灾害的发生、及时传递灾情信息、实际参与救灾行动等减灾救灾各个环节中必不可少的手段,发挥着越来越重大的作用。     

基于SMS的气象灾害短时临近自动预警系统设计与实现

目前,各种气象灾害频发,气象灾害造成的损失也越来越大。针对目前已经投入业务运行的各种气象探测设备观测数据进行自动实时分析并根据灾害性天气发生时气象数据达到的阈值条件通过手机短信发送相应气象灾害信息到各级气象预报服务业务人员手机,以便其在第一时间内进一步分析和处理,从而有效防范和应对各种气象灾害的发生。系统开发完毕并投入业务应用以来,根据气象业务应用实际情况表明系统在气象灾害预警、防灾减灾等业务中发挥了积极作用。     

光学遥感影像成像模拟研究综述

光学遥感影像成像模拟技术在航天器设计、卫星参数选择等方面有着积极的使用价值,可以极大地促进遥感事业的发展.本文从图像合成模拟模型、遥感物理模拟模型以及虚拟现实模拟模型对光学遥感影像成像模拟技术进行了介绍,对模拟过程中的主要影响因素、仍然存在的问题进行了分析,最后总结了光学遥感模拟技术的应用.     

An efficient utilization of intermittent surface–satellite optical links by using mass storage device embedded in satellites

Recently, earth observation system by using satellite network has attracted much attention due to its wide coverage and disaster resistance. Although the system is useful for collecting various data, which have an effect on a natural disaster, ecology and so forth, earth observation satellite hardly send the collected observation data to the ground station. This is because that the earth observation satellite needs to orbit near surface of the earth to get high-precision data, and it limited the time that can be used to send the observed data traffic to the ground station. Additionally, the amount of the observed data drastically increase in these days. Thus, we focus on the data relay satellite using optical communication in this network. By relaying observed data to traffic to the relay satellite, which has geostationary orbit, it is possible to increase the chance of sending data for the observation satellite due to the wide coverage of the relay satellite. In addition, laser light that is used in optical communication in satellite network has high frequency and it can deliver large data compared with radio wave. However, laser light is greatly influenced by atmosphere, and optical link capacity between satellite and ground station drastically changes according to weather condition. Therefore, we propose a new data traffic control method to use the network constructed by satellites which has mass storage device effectively according to the condition of optical downlink between satellite and optical ground station. The effectiveness of the proposed method is evaluated with numerical result.     

多观测卫星任务调度系统的设计与实现

随着卫星应用技术的飞速发展,对地观测卫星在减灾防灾、环境保护和军事等领域的应用也更加广泛.该文在卫星仿真工具包(STK)的基础上设计并实现了多观测卫星任务调度系统,描述了系统的结构和功能,重点介绍了任务描述、调度引擎等重要模块的设计方法和实现过程,并用甘特图等方式实现了系统的结果展现,取得了良好的效果,最后对系统的特点和发展方向做出了总结和展望.     

基于Web的资源卫星覆盖查询设计与仿真

卫星覆盖是卫星应用中最主要的环节之一,它将决定卫星的最终服务范围.根据卫星和地球间的关系可以将卫星分为两类:静止星和动态星;静止星的覆盖范围理论上足个常量,动态星的覆盖范围随着时间而动态地改变.为了方便用户实时查询过境的动态卫星,提到一种基于网络的卫星覆盖查询系统.根据卫星类别分别提出了两种传感器覆盖模型,并简单描述了网络访问的实现方式,从而实现了对卫星覆盖的动态仿真.为了验证仿真结果的有效性,将其结果和卫星软件STK覆盖模块仿真结果进行了比较,整体得到了较好的仿真效果.     

Automatic on-orbit geometric calibration framework for geostationary optical satellite imagery using open access data

Due to a variety of factors, long-term on-orbit geometric calibrations must be performed on the geostationary optical satellite to meet the subsequent high-precision geometric processing requirements. Designing a fully automatic on-orbit geometric inspection and calibration process has great application value. In this paper, we use open-access geographic information data to achieve a more robust automatic on-orbit geometric calibration for the imaging characteristics of the geostationary optical satellite. Experiments with the high-resolution geostationary optical satellite GaoFen4. Results show that the process designed in this paper enables automatic on-orbit geometric calibration of the geostationary optical satellite and obtain high-accuracy calibration parameters, thus effectively improving the geometric positioning accuracy of satellite imagery.     

Evaluation of remotely sensed actual evapotranspiration products from COMS and MODIS at two different flux tower sites in Korea

Estimating the evapotranspiration (ET) is a requirement for water resource management and agricultural productions to understand the interaction between the land surface and the atmosphere. Most remote-sensing-based ET is estimated from polar orbiting satellites having low frequencies of observation. However, observing the continuous spatio-temporal variation of ET from a geostationary satellite to determine water management usage is essential. In this study, we utilized the revised remote-sensing-based Penman–Monteith (revised RS-PM) model to estimate ET in three different timescales (instantaneous, daily, and monthly). The data from a polar orbiting satellite, the Moderate Resolution Imaging Spectroradiometer (MODIS), and a geostationary satellite, the Communication, Ocean, and Meteorological Satellite (COMS), were collected from April to December 2011 to force the revised RS-PM model. The estimated ET from COMS and MODIS was compared with measured ET obtained from two different flux tower sites having different land surface characteristics in Korea, i.e. Sulma (SMC) with mixed forest and Cheongmi (CFC) with rice paddy as dominant vegetation. Compared with flux tower measurements, the estimated ET on instantaneous and daily timescales from both satellites was highly overestimated at SMC when compared with the flux tower ET (Bias of 41.19–145.10 W m^?2 and RMSE of 69.61–188.78 W m^?2), while estimated ET results were slightly better at the CFC site (Bias of –27.28–13.24 W m^?2 and RMSE of 45.19–71.82 W m^?2, respectively). These errors in results were primarily caused due to the overestimated leaf area index that was obtained from satellite products. Nevertheless, the satellite-based ET indicated reasonable agreement with flux tower ET. Monthly average ET from both satellites showed nearly similar patterns during the entire study periods, except for the summer season. The difference between COMS and MODIS estimations during the summer season was mainly propagated due to the difference in the number of acquired satellite images. This study showed that the higher frequency of COMS than MODIS observations makes it more ideal to continuously monitor ET as a geostationary satellite with high spatio-temporal coverage of a geostationary satellite.     

利用静止气象卫星监测浙江海上大雾

卫星遥感是监测大雾的重要手段,利用静止气象卫星监测海上大雾,可以得到时间分辨率比极轨卫星更高、空间覆盖比地面观测更连续的大雾产品。采用分级判识太阳高度角阈值和归一化大雾指数(NDFI)的方法,反演了2008年至今浙江海雾的逐时分布,并将静止卫星(MTSAT)遥感大雾监测结果与近5年地面大雾观测和2013年春季能见度自动观测记录作对比,结果显示遥感反演的总体精度分别为68.4%和69.6%,且空间分布上与地面观测相吻合。表明该方法可突出雾与其他地物的差异,且判识方法简单、实用性强、准确率较高;实时监测浙江海上大雾是可行的,具有良好的业务应用前景。不同时段正确率的验证结果显示,该方法更适用于海雾频发的冬春季以及白天的监测。     

A model, a heuristic and a decision support system to solve the scheduling problem of an earth observing satellite constellation

China plans to launch four small optical satellites and four small SAR satellites to form a natural disaster monitoring constellation. Data can be obtained by the constellation in all weather conditions for disaster alert and environmental damage analysis. The scheduling problem for the constellation consists of selecting and timetabling the observation activities to acquire the requested images of the earth surface and scheduling the download activities to transmit the image files to a set of ground stations. The scheduling problem is required to be solved every day in a typical 1-day horizon and it must respect complex satellite operational constraints as well as request preferences, such as visibility time windows, transition time between consecutive observations or downloads, memory capacity, energy capacity, polygon target requests and priorities. The objective is to maximize the rewards of the images taken and transmitted. We present a nonlinear model of the scheduling problem, develop a priority-based heuristic with conflict-avoided, limited backtracking and download-as-needed features, which produces satisfactory feasible plans in a very short time. A decision support system based on the model and the heuristic is also provided. The system performance shows a significant improvement with respect to faster and better scheduling of an earth observing satellite constellation.     

A method for cross‐calibrating geostationary and polar orbiting satellite sensors in the infrared windows

The forward radiative transfer routine has been used to remove the artefact caused by modulation on meteorological satellite‐sensor responses. This paper describes a direct method where images observed by the infrared channels aboard the Multi‐functional Transport Satellite (MTSAT‐1R) and Fengyun‐2C (FY‐2C) geostationary satellites are compared with those by the Advanced Very High Resolution Radiometer (AVHRR) sensor aboard the National Oceanic and Atmospheric Administration (NOAA) polar‐orbiting satellites. The calibration differences between the polar orbiting and the geostationary satellites are found to be within 1 K of each other.