A novel solution for outlier removal of ICESat altimetry data： a case study in the Yili watershed, China

作     者：Xiaodong HUANG Hongjie XIE Guoqing ZHANG Tiangang LIANG 

作者机构：State Key Laboratory of Grassland Agro-ecology System College of Pastoral Agriculture Science and Technology Lanzhou University Lanzhou 730020 China Laboratory for Remote Sensing and Geoinformatics Department of Geological Sciences University of Texas at San Antonio San Antonio TX 78249 USA Key Laboratory of Tibetan Environment Changes and Land Surface Processes Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing 100101 China 

出 版 物：《Frontiers of Earth Science》 (地球科学前沿（英文版）)

年 卷 期：2013年第7卷第2期

页      面：217-226页

核心收录：

学科分类：090802[农学-捕捞学] 0908[农学-水产] 08[工学] 09[农学] 0815[工学-水利工程] 

基　　金：We thank NASA's ICESat Science Project and the NSIDC for distribution of the ICESat data. This work was in part supported by the National Natural Science Foundation of China (Grant Nos. 41101337 and 31228021 ) and the Cultivation Fund of the Key Scientific and Technical Innovation Project  Ministry of Education of China (No. 708089). Authors want to thank Donghui Yi (NASA/Goddard) for helpful discussion on the early stage of the study and Ning Lv (IGSNRR/CAS) for help in developing the IDL code when he was a visiting scholar at UTSA 

主　　题：ICESat outliers and removal Yili watershed lake level 

摘      要：Due to the influence of cloud and saturated waveforms, ICESat data contain many contaminated elevation data that cannot be directly used in examining surface elevation and change. This study provides a novel solution for removing bad data and getting clean ICESat data for land applications by using threshold values of reflectivity, saturation, and gain directly from ICESat＇s GLAS （Geoscience Laser Alteimeter System） 01, 05, and 06 products. It is found that each laser campaign needs different threshold compositions to assure qualified ICESat data and that bad data removal rates range from 9.6% （laser 2A） to 62.3% （laser 2B） for the test area in the Yili watershed, China. These thresholds would possibly be used in other regions to extract qualified ICESat footprints for land applications. However, it is recommended to use the steps proposed here to further examine the transferability of threshold values for other regions of different elevations and climate regimes. As an example, the resulting ICESat data are applied to examine lake level changes of two lakes in the study area.