德国新型雷达遥感系统TerraSAR-X介绍

2007-06-15,德国雷达遥感卫星TerraSAR-X在俄罗斯位于Kazachstan的Baikonur发射中心发射成功.4d后,第一批雷达数据成功传回到位于德国Neustrelitz的德国遥感数据中心(DFD).发射后8周,卫星系统已经完全正常运行,并传回了超过2 500幅雷达图像.第一批影像产品已经由DLR遥感信息处理研究所(IMF)制作完成.     

TerraSAR-X/TanDEM-X雷达遥感计划及其应用

介绍了德国航天局即将发射的TerraSAR-X雷达卫星遥感计划和将要在近期实施的TanDEM-X雷达遥感计划,分析了该计划的工作模式和应用。     

世界航天遥感技术现状、发展趋势及油气遥感应用方向

世界航天遥感技术发展迅速,掌握卫星发射技术和具备卫星发射能力的国家越来越多,其中,高分辨率小型商业卫星和雷达卫星已经成为重要的遥感信息源;高光谱分辨率遥感将是现今和下个世纪的发展方向。本文总结了世界航天遥感技术现状,分析了今后的发展趋势,提出了油气遥感应用的研究方向     

全球首颗高分辨率雷达卫星COSMO—SkyMed引入我国

随着商用高分辨率遥感卫星在各行业应用的不断深入，卫星数据源如何满足日益增长的应用需求已经是一个亟待解决的问题。高分辨率雷达遥感卫星由于具有全天候、全天时对地观测的能力等特点，近2a来备受关注，并相继有高分辨率雷达卫星被发射上空。     

RADARSAT计划简介

1 前言将于1995年初发射的RADARSAT是加拿大首次发射的遥感卫星,也将是世界上第一颗可操作的雷达卫星。它具有可调节的分辨率和地面覆盖宽度,因此,可根据用户要求选择侧视雷达的天线方式及入射角等参数,以满足不同的应用要求。并且,数据既可以作为独立的信息源,亦可和其它的卫星影像数据联合使用,在世界范围的资源管理和环境监测方面,RADARSAT影像将具有巨大的使     

航天简讯

(1)俄拟推出 1ｍ商业遥感卫星系列。俄罗斯赫鲁尼切夫国营研究与生产航天中心计划推出名为“监视者”(Ｍｏｎｉｔｏｒ)的 1ｍ分辨率商业遥感卫星系列。这些卫星基于该中心的“快艇”(Ｙａｋｈｔａ)卫星平台 ,重约 6 75～ 85 5ｋｇ ,将用“轰鸣”火箭发射 ,运行在 4 80ｋｍ高的太阳同步极地轨道上。据称 ,利用仅 6 5ｃｍ的小型ＶＳＡＴ(甚小孔径终端 )个人地面接收终端即可直接接收到这些卫星的图像数据。(2 )“雷达卫星 2”平台通过设计评审。 2 0 0 2年 1月 8日 ,主管加拿大“雷达卫星 2”的ＭＤＡ公司说 ,该卫星平台已通过了严格的设计评…     

我国测绘卫星的发展思路和应用展望

国家测绘局经过多年的研究开发,已基本形成了卫星测图的科学生产工艺,对于更大程度上发挥卫星遥感应用潜力起到了积极推动作用。为适应遥感技术的发展,国家测绘局已经于2005年编制了《测绘部门十一五航天规划(草案)》,测绘卫星计划包括研制发射我国自主的测绘系列卫星和建立自主版权的测绘卫星综合应用服务体系。高分辨率测绘系列卫星包括:高分辨率光学立体测图卫星、干涉雷达卫星、激光测高卫星和重力卫星等。随着我国航天事业和卫星制造技术的蓬勃发展,未来的卫星测绘应用能力将得到进一步加强。     

陆地卫星的回顾及其新计划

<正> 一、前言美国陆地卫星计划已经历了两个成功的阶段:第一阶段建造和发射了陆地卫星-1、-2和-3。重要的标志是获得了高质量的多光谱扫描仪(MSS)图象,推动世界进入遥感的试验应用;第二阶段建造和发射了陆地卫星-4、-5,使遥感应用有了重大的进展,因为卫星内增加一台新的传感器——专题制图仪(TM)。1985年开始,进行第三阶段陆地卫星计划,将建造陆地卫星-6和-7。它们有许多重要的特性,除发挥多光谱传感器的优势外,还顾及海洋的遥感,提高光谱和空间分解力,更深入地扩大遥感的应用。回顾陆地卫星的发展,对比陆地卫星新计划的设计特性,使我们认识到遥感科学技术和应用正向更高的水平发展。     

卫星遥感技术的发展和最新成就

本文概述 1972～ 1999年卫星遥感发展情况及其在地球科学中的应用。重点在于介绍它的最新成就 ,如美国陆地卫星第 7号 (L ANDSAT- 7)和加拿大雷达卫星第 1号 (RADARSAT- 1) ,它们代表卫星遥感的最新发展水平。     

美国SeaStar海洋水色卫星简介

美国海洋水色卫星SeaStar是继1978年发射的Nimbus-7(雨云)卫星后的国际上第2颗海洋水色专用卫星,计划于1995年年初发射。我国国家海洋局第二海洋研究所已获NASA批准,将建站接收该卫星资料。本文介绍SeaStar卫星及其轨道参数和星上装载的海洋宽视场水色扫描仪有关情况及其遥感资料的接收和应用情况。     

天绘二号卫星工程设计与实现

天绘二号卫星系统是我国首个基于干涉合成孔径雷达技术的微波测绘卫星系统,也是我国第1个近距离编队卫星系统,是国际上继德国TanDEM-X系统后的第2个微波干涉测绘卫星系统,并在国际上首次提出了通过设计双频成像解决干涉相位绝对模糊问题的方法,彻底摆脱了对地面控制数据的依赖。该系统工作于X频段,设计分辨率为3 m,处于500 km的太阳同步轨道,由两颗对等的卫星组成,采用异轨道面卫星编队、一发双收雷达收发模式的技术体制,可以快速测制全球数字表面模型和雷达正射影像。本文通过对干涉基线体制、卫星编队构型及雷达收发模式的选择,提出了天绘二号卫星技术体制;并从系统任务、主要性能及组成3个方面进行了工程设计;从总体论证、关键技术攻关及验证、型号研制3个阶段阐述了工程实现情况;最后介绍了卫星系统在轨测试验证情况。测试结果表明,所有指标达到了工程设计要求,产品精度与TanDEM-X系统相当,满足1：5万比例尺测图精度要求,从而验证了天绘二号卫星工程设计思路正确,工程实现的方法合理可行。     

北京1号小卫星图像噪声评估

从理论和试验方面对图像的噪声评估方法进行了分析。结合北京1号小卫星特性, 进行了该类方法应用效能的评价, 讨论了分块评估噪声方法的最佳参数设置。选取满足噪声评估环境的图像, 实现了综合不同地表覆盖条件的北京1号小卫星图像噪声的评估。噪声评估结果与在轨测试情况的对比表明, 北京1号小卫星经过近3年的运行, 仍保持了较好的性能。     

重复轨道SIR-C极化干涉SAR数据植被覆盖区土壤水分反演研究

从理论和试验方面对图像的噪声评估方法进行了分析。结合北京1号小卫星特性, 进行了该类方法应用效能的评价, 讨论了分块评估噪声方法的最佳参数设置。选取满足噪声评估环境的图像, 实现了综合不同地表覆盖条件的北京1号小卫星图像噪声的评估。噪声评估结果与在轨测试情况的对比表明, 北京1号小卫星经过近3年的运行, 仍保持了较好的性能。     

BDS-2/BDS-3的MEO卫星B3I频率数据质量对比分析

针对目前BDS-2/BDS-3数据质量情况,本文基于IGS连续跟踪站实测数据,从数据完整率、信噪比以及多路径三个方面对比分析了BDS-2/BDS-3的MEO卫星的B3I频率的数据质量。经分析发现,BDS-3新卫星的发射增加了北斗系统的服务范围,BDS-3卫星的数据完整率与信噪比要高于BDS-2,BDS-3卫星的多路径效应小于BDS-2,没有在BDS-3卫星中观测到存在于BDS-2卫星中的系统偏差。     

Coseismic surface deformation of the 2014 Napa earthquake mapped by Sentinel-1A SAR and accuracy assessment with COSMO-SkyMed and GPS data as cross validation

ABSTRACT

The new land observation satellite Sentinel-1A was launched on 25 April 2014 with a C-band synthetic aperture radar (SAR) sensor, which has the significant enhancements in terms of revisit period and high resolution. The Mw 6.1 Napa, California earthquake occurring on 24 August 2014, almost 4 months after the launch, is the first moderate earthquake imaged by the Sentinel-1A. This provides an opportunity to map the coseismic deformation of the event and evaluate the potential of Sentinel-1A SAR for earthquake study. Two techniques including the interferometric SAR (InSAR) and pixel offset-tracking (PO) are, respectively, employed to map the surface deformation along the radar line of sight (LOS), azimuth and slant-range directions. The cross comparison between Sentinel-1A InSAR LOS deformation and GPS observations indicates good agreement with an accuracy of ～2.6?mm. We further estimate the earthquake source model with the external COSMO-SkyMed InSAR and GPS data as constraints, and forward calculate the surface deformation as cross validation with the Sentinel-1A observations. The comparison between the observed and modeled deformation shows that the Sentinel-1A measurement accuracy can achieve 1.6?cm for InSAR technique along LOS direction, and 6.3 and 6.7?cm for PO along azimuth and range directions, respectively.     

Orthorectification of VHR optical satellite data exploiting the geometric accuracy of TerraSAR-X data

Orthorectification of satellite data is one of the most important pre-processing steps for application oriented evaluations and for image data input into Geographic Information Systems. Although high- and very high-resolution optical data can be rectified without ground control points (GCPs) using an underlying digital elevation model (DEM) to positional root mean square errors (RMSEs) between 3 m and several hundred meters (depending on the satellite), there is still need for ground control with higher precision to reach lower RMSE values for the orthoimages. The very high geometric accuracy of geocoded data of the TerraSAR-X satellite has been shown in several investigations. This is due to the fact that the SAR antenna measures distances which are mainly dependent on the terrain height and the position of the satellite. The latter can be measured with high precision, whereas the satellite attitude need not be known exactly. If the used DEM is of high accuracy, the resulting geocoded SAR data are very precise in their geolocation. This precision can be exploited to improve the orientation knowledge and thereby the geometric accuracy of the rectified optical satellite data. The challenge is to match two kinds of image data, which exhibit very different geometric and radiometric properties. Simple correlation techniques do not work and the goal is to develop a robust method which works even for urban areas, including radar shadows, layover and foreshortening effects. First the optical data have to be rectified with the available interior and exterior orientation data or using rational polynomial coefficients (RPCs). From this approximation, the technique used is the measurement of small identical areas in the optical and radar images by automatic image matching, using a newly developed adapted mutual information procedure followed by an estimation of correction terms for the exterior orientation or the RPC coefficients. The matching areas are selected randomly from a regular grid covering the whole imagery. By adjustment calculations, parameters from falsely matched areas can be eliminated and optimal improvement parameters are found. The original optical data are orthorectified again using the delivered metadata together with these corrections and the available DEM. As proof of method the orthorectified data from IKONOS and ALOS-PRISM sensors are compared with conventional ground control information from high-precision orthoimage maps of the German Cartographic Survey. The results show that this method is robust, even for urban areas. Although the resulting RMSE values are in the order of 2-6 m, the advantage is that this result can be reached even for optical sensors which do not exhibit low RMSE values without using manual GCP measurements.     

Effect of Long Waves on Ku-Band Ocean Radar Backscatter at Low Incidence Angles Using TRMM and Altimeter Data

This letter uses a large ocean satellite data set to document relationships between Ku-band radar backscatter (sigma_o) of the sea surface, near-surface wind speed (U), and ocean wave height (SWH). The observations come from satellite crossovers of the Tropical Rainfall Mapping Mission (TRMM) Precipitation Radar (PR) and two satellite altimeters, namely: 1) Jason-1 and 2) ENVISAT. At these nodes, we obtain TRMM clear-air normalized radar cross-section data along with coincident altimeter-derived significant wave height. Wind speed estimates come from the European Centre for Medium-Range Weather Forecast. TRMM PR is the first satellite to measure low incidence Ku-band ocean backscatter at a continuum of incidence angles from 0deg to 18deg. This letter utilizes these global ocean data to assess hypotheses developed in past theoretical and field studies.     

State-of-the-art of elevation extraction from satellite SAR data

Relative or absolute elevation extraction from satellite radar data has been an active research topic for more than 20 years. Various investigations have been made on different methods depending on the predominant “fashion” and data availability, leading each time to new developments to improve the capability and the applicability of each method. The paper presents an update of the state-of-the-art of elevation extraction from satellite SAR data. The performance and limitations of four different methods (clinometry, stereoscopy, interferometry and polarimetry) are reviewed, as well as their applicability to different satellite SAR sensors. Their advantages and disadvantages and how they are addressed during the data processing are also analysed. Finally, concluding remarks look at the complementarity aspects of each method to make the best use of the existing and future radar data for elevation extraction.