A new digital elevation model (DEM) dataset of the entire Antarctic continent derived from ICESat-2
A new digital elevation model (DEM) dataset of the entire Antarctic continent derived from ICESat-2
复制标题
从ICESat-2获得的整个南极大陆的新数字高程模型（DEM）数据集
DOI：
10.5194/essd-14-3075-2022
复制
发表时间：
2022-07
影响因子：
11.4
通讯作者：
Xiaoyi Shen;C. Ke;Yubin Fan;Lhakpa Drolma
中科院分区：
文献类型：
--
作者：
Xiaoyi Shen;C. Ke;Yubin Fan;Lhakpa Drolma
抽象的。南极数字高程模型（DEM）对于野外工作、冰的运动跟踪和冰盖的数字建模至关重要。在过去的30年里，已经出版了几个由卫星数据得出的南极DEM。然而，这些DEM要么具有粗糙的空间分辨率，要么具有跨越数年的聚合观测，这限制了它们的进一步科学应用。在这项研究中，新一代的卫星激光高度计冰，云，和陆地高程卫星-2（ICESat-2）被用来生成一个新的南极冰盖和冰架的DEM。从2018年11月到2019年11月，大约4.69 × 109个ICESat-2测量点用于基于时空拟合方法以500米和1公里的分辨率估计地表高程。南极洲大约74%的区域被观测到，其余的观测间隙使用正态克里金法进行插值。数字高程模型是由500米和1公里网格单元中的估计高程形成的，最后以500米的分辨率张贴。美国国家航空航天局（NASA）冰桥行动（OIB）的机载数据被用来评估所产生的南极DEM（以下称为ICESat-2 DEM）在个别南极地区和表面类型。总体而言，约5.2 × 106个OIB测量点产生的中位偏差为-0.19 m，均方根偏差为10.83 m。ICESat-2 DEM的准确性和不确定性与表面坡度和粗糙度有关，在平坦的冰盖内部发现了更可靠的估计。ICESat-2数字高程模型与从测高、立体摄影测量和干涉测量中获得的其他数字高程模型具有可比性。在与全球导航卫星系统（全球定位系统和俄罗斯全球轨道导航卫星系统）动态断面的高程测量值进行比较时，也发现了类似的结果。高精度的高程和每年更新的能力使ICESat-2 DEM成为现有南极DEM组的补充，并可进一步用于其他科学应用。生成的ICESat-2 DEM（包括不确定性地图）可从中国科学院青藏高原研究所国家青藏高原数据中心下载，网址为https://data.tpdc.ac.cn/en/disallow/9427069c-117e-4ff8-96e0-4b18eb7782cb/（最后访问时间：2022年6月27日）（Shen et al.，2021 a，https：//doi.org/10.11888/Geogra.tpdc.271448）。
Abstract. Antarctic digital elevation models (DEMs) are essential for fieldwork, ice motion tracking and the numerical modelling of the ice sheet. In the past 30 years, several Antarctic DEMs derived from satellite data have been published. However, these DEMs either have coarse spatial resolution or aggregate observations spanning several years, which limit their further scientific applications. In this study, the new generation satellite laser altimeter Ice, Cloud, and Land Elevation Satellite-2 (ICESat-2) is used to generate a new Antarctic DEM for both the ice sheet and ice shelves. Approximately 4.69 × 109 ICESat-2 measurement points from November 2018 to November 2019 are used to estimate surface elevations at resolutions of 500 m and 1 km based on a spatiotemporal fitting method. Approximately 74 % of Antarctica is observed and the remaining observation gaps are interpolated using the normal kriging method. The DEM is formed from the estimated elevations in 500 m and 1 km grid cells, and is finally posted at the resolution of 500 m. National Aeronautics and Space Administration (NASA) Operation IceBridge (OIB) airborne data are used to evaluate the generated Antarctic DEM (hereafter called the ICESat-2 DEM) in individual Antarctic regions and surface types. Overall, a median bias of −0.19 m and a root-mean-square deviation of 10.83 m result from approximately 5.2 × 106 OIB measurement points. The accuracy and uncertainty of the ICESat-2 DEM vary in relation to the surface slope and roughness, and more reliable estimates are found in the flat ice sheet interior. The ICESat-2 DEM is comparable to other DEMs derived from altimetry, stereophotogrammetry and interferometry. Similar results are found when comparing to elevation measurements from kinematic Global Navigation Satellite System (GNSS) (GPS and the Russian GLONASS) transects. The elevations of high accuracy and ability of annual updates make the ICESat-2 DEM an addition to the existing Antarctic DEM groups, and it can be further used for other scientific applications. The generated ICESat-2 DEM (including the map of uncertainty) can be downloaded from National Tibetan Plateau Data Center, Institute of Tibetan Plateau Research, Chinese Academy of Sciences at https://data.tpdc.ac.cn/en/disallow/9427069c-117e-4ff8-96e0-4b18eb7782cb/ (last access: 27 June 2022) (Shen et al., 2021a, https://doi.org/10.11888/Geogra.tpdc.271448).