【摘要】 最新的数字高程模型(DEM)产品在灾害防治、城市管理等诸多领域中扮演着重要角色。利用机载或低地球轨道(LEO)的星载干涉合成孔径雷达(InSAR)生成DEM已被证明是可行且极具价值的方法。然而,受成本和卫星重返周期的限制,该技术难以频繁(如每天)生成或更新大区域范围(如大陆尺度或更大范围)的DEM。由于对地同步合成孔径雷达(GEOSAR)卫星运行于地球静止轨道,因此它们能以相当短的重返时间(每天或更短)观测同一地面区域,这为实现生成每日DEM这一理想但目前难以实现的目标提供了潜在可能。为此,本文系统地分析了利用GEOSAR卫星生成的每日DEM产品质量。结果表明:GEOSAR卫星生成的每日DEM产品精度通常远低于利用传统低轨星载合成孔径雷达(SAR)获得的DEM产品。因此,研究GEOSAR DEM生成过程中的误差削弱方法显得至关重要。更多还原

【Abstract】 Up-to-date digital elevation model(DEM) products are essential in many fields such as hazards mitigation and urban management. Airborne and low-earth-orbit(LEO) space-borne interferometric synthetic aperture radar(InSAR) has been proven to be a valuable tool for DEM generation. However,given the limitations of cost and satellite repeat cycles, it is difficult to generate or update DEMs very frequently(e.g., on a daily basis) for a very large area(e.g., continental scale or greater). Geosynchronous synthetic aperture radar(GEOSAR) satellites fly in geostationary earth orbits, allowing them to observe the same ground area with a very short revisit time(daily or shorter). This offers great potential for the daily DEM generation that is desirable yet thus far impossible with space-borne sensors. In this work,we systematically analyze the quality of daily GEOSAR DEM. The results indicate that the accuracy of a daily GEOSAR DEM is generally much lower than what can be achieved with typical LEO synthetic aperture radar(SAR) sensors; therefore, it is important to develop techniques to mitigate the effects of errors in GEOSAR DEM generation.更多还原