Comparison of ICESat data with airborne laser altimeter measurements over Arctic sea ice
Comparison of ICESat data with airborne laser altimeter measurements over Arctic sea ice
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DOI：
10.1109/tgrs.2008.916639
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发表时间：
2008-07-01
影响因子：
8.2
通讯作者：
Miller, Jeffrey
中科院分区：
文献类型：
--
作者：
Kurtz, Nathan T.;Markus, Thorsten;Miller, Jeffrey
将NASA的冰、云和陆地高程卫星(ICESat)测量的表面高度和粗糙度与2006年3月EOS Aqua高级微波扫描辐射计海冰验证活动期间在阿拉斯加北部北极海冰上进行的高分辨率航空激光高度计测量进行了比较。高程测量的比较表明，对于单次拍摄，它们与0.9左右的相关性非常一致，偏差小于2厘米。研究发现，当采用跑步方式时，差异会迅速减小。粗糙度测量的比较表明，两个数据集之间存在显著差异，ICESat通常具有较高的值。粗糙度值在单炮的基础上只是中等程度的相关，但对数据应用跑动方法显著地将相关性提高到高达0.9。为了将高程测量转换为冰雪干板，利用高分辨率激光高度计数据以及使用较低分辨率ICESat数据的几种方法估计了海面高程。在最佳条件下，即当存在大于ICESat足迹的引线时，ICESat和机载地形图测绘器得出的干舷在2厘米内一致。对于其他地区，ICESat往往会低估干舷高达9厘米。
Surface elevation and roughness measurements from NASA's Ice, Cloud, and land Elevation Satellite (ICESat) are compared with high-resolution airborne laser altimeter measurements over the Arctic sea ice north of Alaska, which were taken during the March 2006 EOS Aqua Advanced Microwave Scanning Radiometer sea ice validation campaign. The comparison of the elevation measurements shows that they agree quite well with correlations of around 0.9 for individual shots and a bias of less than 2 cm. The differences are found to decrease quite rapidly when applying running means. The comparison of the roughness measurements show that there are significant differences between the two data sets, with ICESat generally having higher values. The roughness values are only moderately correlated on an individual-shot basis, but applying running means to the data significantly improves the correlations to as high as 0.9. For the conversion of the elevation measurements into snow-ice freeboard, ocean surface elevation estimates are made with the high-resolution laser altimeter data, as well as several methods using lower resolution ICESat data. Under optimum conditions, i.e., when leads that are larger than the ICESat footprint are present, the ICESat- and Airborne Topographic Mapper-derived freeboards are found to agree to within 2 cm. For other areas, ICESat tends to underestimate the freeboard by up to 9 cm.