基于ICESat-2和GSWD数据获取动态水域地形图的方法

传统的湖泊、海岸带测深主要是基于船载多波束系统或者机载激光雷达测深系统,但这些方式测量成本较高。因此提出了一种仅利用卫星观测数据,实现高分辨率动态水域地形图的获取方法,该方法基于ICESat-2单光子激光点云和Landsat图像数据的全球地表水数据集(GSWD),对所获取的高精度激光沿轨轮廓线与多年期湖泊水域边界等高线进行融合匹配。以美国最大的水库米德湖为实验区域,生成高程范围约为34 m的地形图结果,覆盖面积超过307 km~2,水平分辨率为30 m;在与机载激光雷达数据等现场实测结果的对比中,所绘制地形图均方根误差约为2 m。研究方法有望为水位波动较大或水质相对较好的内陆水体(例如湖泊)和沿海地区(例如潮间带)提供一种新的水陆交界区域地形图获取方法。

Surveying and Mapping the Topography for Dynamic Water Areas Using ICESat-2 and GSWD

In tradition,lake and coastal bathymetry is normally obtained by shipborne multiple-beam echo sounders and airborne bathymetric lidars,both of which are high-cost approaches.In this paper,a method of obtaining high-resolution bathymetry for dynamic areas is proposed with only satellite remotely sensed datasets.Specifically,using the Ice,Cloud,and Land Elevation Satellite-2 (ICESat-2) lidar data and the Landsat-based Global Surface Water Dataset (GSWD),the detected along-track lidar profiles are geographically matched with the lake boundary contours of many years.This method is implemented in Lake Mead,which is the largest reservoir of USA.The produced bathymetric map in Lake Mead has a dynamic area over 307km²,elevation ranging over 34m,and a resolution of 30m.Compared with the in-situ measurements based on airborne lidars,the produced lake bathymetry in general achieved the accuracy of approximately 2 m in elevation.The derived method is very promising to obtain the bathymetric map for inland water bodies such as lakes and reservoirs and coastal areas such as tidal zones where water level fluctuations are strong and the water qualities are clear.