低轨视频卫星成像特性分析

视频卫星主要的特点是以"太空录像"的方式获取连续多帧序列图像,可以实现对某一特定区域的凝视成像,因此特别适用于动态变化监测与运动目标矢量指示。文章以美国"天空卫星"(SkySat)为例,分析了图像模式与视频模式下的主要技术指标,给出了低轨视频卫星光学遥感器的主要技术指标和方案设想。在90s的视频成像时间内,分析了卫星俯仰角机动、姿态稳定度及指向精度等姿态控制特性,给出了视频成像的空间分辨率变化和多帧图像构成立体像对的基高比。最后提出了须要重点解决的关键技术,如大面阵CMOS器件、姿态俯仰敏捷机动能力等。     

高分多模卫星敏捷遥感技术研究及应用

敏捷机动技术是提升高分辨率遥感卫星成像能力的一项核心技术。文章分析了高分辨率遥感卫星发展趋势,提出了基于多种敏捷成像模式的新型观测需求,进而提出卫星平台敏捷机动技术的系统要求。结合中型敏捷遥感卫星公用平台(ZY2000 Remote Sensing Satellite Platform)研制,定义敏捷成像模式,分析平台机动能力,提出了卫星敏捷机动指标要求。针对敏捷机动技术的实现,系统性开展了工作,设计了小惯量的星体结构,开发了基于控制力矩陀螺(CMG)的控制系统和控制算法,采用了敏捷任务规划和管理方案,研制了高刚度太阳翼、大量程陀螺、125 Nms控制力矩陀螺等核心产品,开展了数学和半物理仿真验证。高分多模卫星(GFDM-1)作为中型敏捷遥感卫星公用平台的首发星,实现了敏捷机动技术的应用,验证了多种敏捷成像模式下成像质量满足需求。在轨结果表明:高分多模卫星的敏捷机动能力和成像质量满足设计要求,达到国际先进水平。     

高分多模卫星产品保证工作实践

分析了高分多模卫星敏捷成像任务难、中型敏捷遥感卫星公用平台首飞风险高、设计寿命长可靠性要求高、发射场质量确认模式新等特点;总结了主要产品保证工作措施,如狠抓技术风险识别与控制,严格过程管控与专项试验验证,以及压实发射场质量确认责任。上述措施有效保证了卫星产品质量,可为后续卫星研制开展相关产品保证工作提供借鉴。     

月球遥感立体测绘技术的发展

对国外月球探测测绘历程进行了调研总结，并针对立体观测、干涉雷达测量、扫描激光测绘等3种主要的测绘方案进行分析比较，继而提出适合中国月球探测目标的三维遥感测绘成像技术途径。关键词月球探测三维立体成像测绘研究     

敏捷卫星立体成像覆盖能力分析

成像幅宽确定时,敏捷卫星的覆盖能力仅取决于成像条带长度。根据敏捷卫星的立体成像过程,推导出基于圆形地球模型星下点轨迹下的立体成像条带长度通用公式,分析了敏捷卫星实现立体成像的最小机动能力需求,并推导出立体成像条带长度所对应的姿态机动能力需求通用公式。基于某卫星典型姿态机动能力进行实际应用分析,得到轨道高度、俯仰预置角、立体观测视角数量等因素对其影响规律。分析结果表明:在其他条件相同时,轨道高度增加或俯仰预置角增大,均会带来立体成像条带长度增加,双视立体成像获取的条带长度也大于三视立体成像。文章采用的分析方法和推导出的相关公式,可为敏捷卫星的总体分析设计提供参考。     

微纳卫星光学载荷技术发展综述

阐述了微纳卫星光学载荷从单一摄像头到应用模式多样的综合系统的发展过程。调研了国外微纳卫星光学载荷的发展现状及特点,如轻小型化、紧凑化、观测任务多样化和视频成像,主要表现在低成本商业遥感应用,适于新技术演示验证、光学载荷图像产品的网络应用、商用现货(COTS)技术应用、模块化技术体系等方面。通过归纳总结得出以下启示:我国微纳卫星光学载荷发展应紧跟国际步伐,瞄准低成本商业遥感方向,建立标准化、模块化微纳卫星光学载荷技术体系;发展颠覆性技术(薄膜衍射成像和液晶可调光谱滤光片用于高光谱成像),积极探索微纳卫星光学载荷研制模式的创新。     

敏捷光学卫星多模式推扫成像时的偏流角研究

对运行于太阳同步轨道的以时间延迟积分CCD(TDI-CCD)相机为成像有效载荷的敏捷光学卫星姿态对地指向变化的多模式推扫成像,研究了基于运动学和卫星自身姿态信息的偏流角解算方法。基于线阵TDI-CCD推扫点目标瞬时成像、区域扫描成像和立体成像模式,分析了动态成像过程中的偏流原理。综合运动学和速度矢量方法,推导出了星下点速度矢量在敏感器坐标系中的表达式。数值仿真表明:当相机推扫方向与航迹方向平行时,偏流源于地球自转;当相机推扫方向与航迹方向不平行时,偏流角主要受地表的牵连速度影响。采用姿态偏航控制对偏流角进行调整,可实现敏捷光学卫星执行多模式推扫成像技术。     

高分多模卫星方案设计与技术特点

高分多模卫星是一颗敏捷光学成像卫星,具有全色优于0.5 m/多光谱优于2 m分辨率、1个全色谱段+8个多光谱谱段、无控制点定位精度优于10 m的能力,同时具有多种敏捷成像模式。文章概述了高分多模卫星的方案设计,并总结了卫星的敏捷成像、敏捷机动、图像质量保证、高定位精度保证、微振动抑制、大气同步校正、自主任务管理等技术特点。卫星的成功发射并投入使用,实现了民用光学遥感卫星优于0.5 m高分辨率图像数据的获取能力,可有效推动我国高分辨率对地观测系统建设和空间遥感的定量化应用水平。     

敏捷遥感卫星新型姿态控制精度评估方法

针对新型敏捷遥感卫星地面测试缺乏验证手段问题,文章提出一种针对敏捷机动成像过程的新型姿态控制精度评估方法,通过设计星地模型算法,根据卫星的定轨数据和高精度姿态数据计算,可得到星载相机成像点在地固坐标系(ECF)的坐标,并引入地表高程数据以提高计算精度,进行成像点位置精度评估,即姿态指向精度评估;通过计算地表镜下点运动速度等衍生参数,进行载荷成像质量评估。与同条件下地面任务规划数据比对,算法精度误差在10米量级,远小于卫星姿态指向误差导致的成像位置偏离,满足地面分析验证精度需求。该套算法已应用于遥感公用平台、某卫星姿态敏捷机动技术地面验证工作。     

月球遥感立体测绘技术的发展

对国外月球探测测绘历程进行了调研总结,并针对立体观测、干涉雷达测量、扫描激光测绘等3种主要的测绘方案进行分析比较,继而提出适合中国月球探测目标的三维遥感测绘成像技术途径。     

商用高分辨率光学遥感卫星及平台技术分析

调研了国外近十年发射的商用高分辨率光学遥感卫星,较为全面、详细地对比了欧美典型的商业光学遥感卫星的技术性能、指标,总结了其发展思路,并对其卫星及平台技术的发展进行了分析,提出了我国该领域技术发展的建议。     

星上遥感影像在轨处理进展研究

从星地数传、高时敏任务等对星上遥感影像在轨处理的需求出发,本文对美国、欧洲以及国内主要的星上遥感影像在轨处理进展进行了研究;以此为基础,结合星上遥感影像在轨处理框架与深度学习等智能处理技术,分析了高性能星上智能处理平台构建、基于深度学习的遥感影像在轨智能处理、多源遥感影像数据在轨融合处理、星地协同数据处理及在轨更新等星上遥感影像在轨处理关键技术;最后,对星上遥感影像在轨处理未来发展趋势进行了总结,为进一步提升遥感卫星在轨应用效能提供参考。     

我国遥感卫星系统发展进阶路径探讨

文章回顾了作为人造地球卫星重要分支的遥感卫星及其相关的遥感技术和遥感产业的国内外发展历程,结合未来技术发展趋势和我国新时代发展需求,分别针对高端卫星和商业卫星,探讨我国卫星遥感系统发展进阶路径,提出值得关注的重大技术方向,旨在为卫星系统规划、遥感载荷部署、卫星应用拓展等提供借鉴.     

Super View-1-China's First Commercial Remote Sensing Satellite Constellation with a High Resolution of 0.5 m

Super View-1 satellite constellation(Super View-1 for short) is the first commercial remote sensing constellation with a resolution down to 0.5 m. It's an important part of the national spatial information infrastructure construction. It will play an important role for the global users providing remote sensing data, application solutions and remote sensing value-added services with its high-resolution and 24-hour observation capability. At present, 4 satellites of the constellation have been successfully launched and networked on orbit. The services cover surveying and mapping, land resource surveying, urban planning, agriculture, forestry, water conservancy, geological mining, environmental monitoring, defense, disaster reduction along with other traditional industries. There are also great potential applications in Mobile Internet, LBS, Smart city, insurance and other emerging professions. The successful operation of Super View-1 breaks the overseas monopoly for commercial high-resolution remote sensing satellite imagery in the China market. It's one of the major achievements in China space science and technology by actively exploring the development of commercial remote sensing markets, which is of strategic significance to the development of China remote sensing satellite business.     

WorldView系列卫星设计状态分析与启示

WorldView 系列卫星是目前世界商业卫星中分辨率较高的光学遥感卫星。文章从卫星总体设计角度介绍了WorldView 系列卫星技术指标,分析了卫星敏捷机动工作能力、构形布局设计、平台和载荷一体化设计和微振动抑制设计等,梳理出国外先进遥感卫星的发展趋势,以此为基础提出了对我国新一代光学遥感卫星的设计启示。     

Current US remote sensing policies: opportunities and challenges

This article examines recent progress in US land remote sensing policies by reviewing the evolution of policy on commercial imaging satellites from 1992 to the present and charting developments in the Landsat programme. Key features of the new (2003) commercial remote sensing policy are described, which go far in addressing the ambiguities of the earlier (PDD-23) framework that, in practice, hampered development of a commercial industry. In the case of Landsat, problems, particularly those of assured data provision, remain. The key to solving them lies in integrating civil, military and commercial elements more coherently, rather than considering them in isolation.     

Expanding global access to civilian and commercial remote sensing data: implications and policy issues

Current and planned developments in the field of civilian and commercial satellite imagery promise a major expansion in international accessibility to remote sensing data and technologies. This paper addresses the implications of the expanding global access to land remote sensing data and their derived products. While atmospheric, meteorological, and oceanographic data is also widely available at cost or free of charge, it is land remote sensing - specifically the unique systems with high-resolution and frequent revisit times - that are of primary concern for international and regional security issues. Military and intelligence satellites are not addressed in this discussion of expansion due to their inherently controlled access, unless such systems also provide commercially available imagery or products (as is the case with some Russian systems).     

国内外遥感卫星发展现状

文章叙述了遥感卫星的发展背景以及在实际应用中的重要意义,并就气象卫星、资源卫星、海洋卫星等几种典型的遥感卫星详细介绍了国内外发展现状。     

国外地球同步轨道遥感卫星发展初步研究

地球同步轨道遥感卫星因具备高时效性及持续探测能力等优势,已成为当前国际遥感卫星领域一个重要的发展方向。文章围绕地球同步轨道遥感卫星,重点针对光学、微波、电子侦察等国际地球同步轨道遥感卫星及卫星平台发展动态、发展趋势开展了调研与分析,梳理出国际发展情况对中国地球同步轨道遥感卫星领域发展的启示。文章从地球同步轨道遥感卫星领域发展战略的高度,进一步提出支撑该领域发展需重点突破的关键技术。     

Cost-driven design of small satellite remote sensing systems*

Earth remote sensing (alongside communications) is one of the key application of Earth-orbiting satellites. Civilian satellites in the LANDSAT and SPOT series provide Earth images which have been used for a vast spectrum of applications in agriculture, meteorology, hydrology, urban planning and geology, to name but a few. In the defence sector, satellite remote sensing systems are a critical tool in strategic and tactical planning – for the countries which can afford them. To date, remote sensing satellites have fallen into one of these two categories: military missions driven by the requirement for very high resolution and orbital agility; and multipurpose civil satellites using general purpose sensors to serve a diverse community of end users. For military-style missions, the drive to high resolution sets the requirements for optics, attitude control and downlink data bandwidth. For civil missions, the requirement to satisfy multiple, diverse user applications forces compromises on spectral band and orbit selection. Although there are exceptions, many small satellite remote sensing missions carry on in this tradition, concentrating on ultra high resolution products for multiple user communities. This results in satellites costing on the order of US $100 M, not optimised for any particular application. This paper explores an alternative path to satellite remote sensing, aiming simultaneously to reduce cost and to optimise imaging products for specific applications. By decreasing the cost of the remote sensing satellite system to a critical point, it becomes appropriate to optimise the sensor's spectral and temporal characteristics to fit the requirements of a small, specialised user base. The critical engineering trade-off faced in a cost driven mission is how to reduce mission cost while still delivering a useful product to the selected user. At the Surrey Space Centre, we have pursued an engineering path using two dimensional CCD array sensors, commercial off-the-shelf lenses and gravity-gradient stabilised microsatellites. In spite of the inherent limitations of such systems, recent successes with the Thai Microsatellite Company's Thai-Phutt satellite show that a system costing in the region of US $3 million, can approach the spectral and spatial characteristics of LANDSAT. Surrey's UoSAT-12 minisatellite (to be launched April, 1999) will further develop this cost-driven approach to provide 10 m panchromatic resolution and 30 m multi-spectral resolution. This paper describes the Thai-Phutt and UoSAT-12 imaging systems, explaining the engineering methods and trade-offs. Although Surrey is presently the only centre presently pursuing such implementations, our paper shows that they deserve wider consideration.