摘要
近十年来,格陵兰和南极冰盖消融增速,两极地区显著变化。美国国家航空航天管理局(NASA)的冰、云和陆地高程卫星(ICESat)自2003年发射至2009年的在轨期间,用于定量分析冰盖和海冰的变化速率,并对这些变化的驱动机制进行检测与监测。ICESat在极地冰雪遥感应用等方面展示出了无可比拟的优势,对精确估算冰盖对海平面上升的年贡献、南北极海冰物质平衡量和计算全球生物总量具有重要的科学意义。冰、云和陆地高程卫星2号(ICESat-2)将在2015年发射,该卫星在ICESat的技术基础上,测高技术和精准度都有了很大的提高。本文评述了ICESat运行情况和应用优势,详尽地介绍了ICESat-2的任务目标、运行参数和技术改进,展望了其将来在极地科学的巨大应用前景。
The primary mission of the Ice,Cloud and Land Elevation Satellite was the global monitoring of polar ice change.ICESat entered a 91-day exact repeat orbit with 33-day subcycles at 600 km altitude and prescribed ground tracks for measuring elevations of ice sheets,sea ice and forest canopy.Global observation systems are being enhanced by ICESat＇s precise measurement.With three big missions,it has obvious superiority in the remote sensing of polar ice and snow.Firstly,it was specifically intended for ICESat to estimate the change in polar icesheet contributions to current and future sea-level rise.ICESat not only assessed the mass balance and mechanisms that drive those changes,but improved predictive ice sheet models.Secondly,as a new and powerful tool,ICESat was designed to measure changes in the spatial patterns of freeboard and thickness of seaice by improving narrow lead detection.Finally,it will contribute much to the vegetation and ecosystem science in terms of estimating forest canopy height and describing topographic relief and vegetation vertical structure.ICESat-2,which is the successor to ICESat,is a subsequent mission planned by NASA.ICESat-2 will be launched in late 2015 and will follow the ICESat orbit.In contrast to ICESat,ICESat-2 will employ micro-pulse multi-beam method.ICESat-2 will apply dense cross-track sampling to determine the effect of surface slope.The sensor will have a high laser repetition rate of 10 kHz,which corresponds to an along-track sampling interval of about 0.7 m.The sensor has 9 beams with varying energy.In contrast to its predecessor,ICESat-2 will measure elevation over steep and very rough areas precisely.
出处
《极地研究》
CAS
CSCD
北大核心
2011年第2期138-148,共11页
Chinese Journal of Polar Research
基金
国家自然科学基金项目“南极Amery冰架底部界面过程与冰架变化研究”(40871035)资助
