一种基于ICESat-2激光光子与SRTM数据的冰川高程变化误差稳健估计方法  

A robust error estimation method for glacier elevation change using ICESat-2 laser photon and SRTM data

作　　者：苏佳利 杨耘[1] 王家禹 刘艳[2,3,4] 魏永强 王锐 杨成生[1] SU Jiali;YANG Yun;WANG Jiayu;LIU Yan;WEI Yongqiang;WANG Rui;YANG Chengsheng(College of Geological Engineering and Geomatics,Chang’an University,Xi’an 710054,China;Institute of Desert Meteorology,China Meteorological Administration,Urumqi 830002,China;Field Scientific Experiment Base of Akdala Atmospheric Background,China Meteorological Administration,Urumqi 830002,China;Key Laboratory of Tree-ring Physical and Chemical Research,China Meteorological Administration,Urumqi 830002,China;Xi’an Research Institute of Surveying and Mapping,Xi’an 710054,China;State Key Laboratory of Geo-information Engineering,Xi’an 710054,China)

机构地区：[1]长安大学地质工程与测绘学院,陕西西安710054 [2]中国气象局乌鲁木齐沙漠气象研究所,新疆乌鲁木齐830002 [3]中国气象局阿克达拉大气本底野外科学试验基地,新疆乌鲁木齐830002 [4]中国气象局树木年轮理化重点实验室,新疆乌鲁木齐830002 [5]西安测绘研究所,陕西西安710054 [6]地理信息工程国家重点实验室,陕西西安710054

出　　处：《冰川冻土》2024年第2期710-721,共12页Journal of Glaciology and Geocryology

基　　金：陕西省自然科学基础研究计划项目(2022JM-163);中央高校基本科研业务费专项资金(300102269205);国家自然科学基金项目(42174032)资助。

摘　　要：针对利用ICESat-2星载光子点云数据进行冰川高程变化监测时,不同地形条件下的ICESat-2激光光子数据质量差异较大导致冰川高程变化量估算误差较大的问题,本文以青藏高原上中国最大的海洋性冰川——恰青冰川为例,联合使用ICESat-2激光测高数据及30 m分辨率SRTM的DEM产品,提出了融合稳健估计准则的多函数拟合冰川高程变化量估算误差改正模型,降低了因地形坡度引起的冰川高程变化量估算误差;进而,估算了2000—2021年间恰青冰川的高程变化速度及质量变化量。结果表明,与对应的传统最小二乘估计结果相比,本文提出的融合稳健估计的函数模型改正效果更优。随后,将改正结果与多种数据进行交叉验证,能够证明该误差改正模型的有效性和可行性。因此,该模型可以有效改善冰川高程和质量变化信息提取的精度,研究结果表明,研究区21年间冰川高程变化速率约为(-0.52±0.56)m·a^(-1),冰川质量变化约为-12773.81×10^(5)t。此外,经过对21年间气象数据的年变化和月变化分析可知,气温和降水量等因素是引起冰川高程变化的主要动因。Glaciers are very sensitive to climatic and environmental changes,and are closely linked to changes in water resources and geological disasters.Under the influence of global warming,the melting of glaciers on the Qinghai-Xizang Plateau and its surrounding areas is on the increase.This paper addresses the problem that the large difference in the quality of ICESat-2 laser photon data under different terrain conditions leads to a large error in the glacier elevation change volume estimation when monitoring glacier elevation change using ICESat-2 satellite photon point cloud data,using Qiaqing Glacier,China’s largest oceanic glacier on the Qinghai-Xizang Plateau,as an example.Using ICESat-2 laser altimetry data and 30 m resolution SRTM DEM products,we propose a multifunction fitting glacier elevation change estimation error correction model with a robust estimation criterion that reduces the glacier elevation change estimation error caused by terrain slope;then,we estimate the elevation change and mass change of Qiaqing Glacier between 2000 and 2021.The results show that the multifunction correction models proposed in this paper can effectively improve the accuracy of the elevation change monitoring results.Meanwhile,the correction effect of the function model incorporating robust estimation is better compared with the corresponding traditional least squares estimation results.Subsequently,the effectiveness and feasibility of the error correction model can be demonstrated by cross-validating the correction results with multiple data.The model can effectively improve the accuracy of extracting glacier elevation and mass change information,and it was concluded that the glacier elevation change rate of the study area during the 21-year period was approximately(-0.52±0.56)m·a^(-1),and the glacier mass change was about-1277.38 million tonnes.In addition,combined with the meteorological data,the annual and monthly average temperature and precipitation data are analyzed,and the overall temperature rise and precipitation

关 键 词：坡度改正 稳健估计 高程变化 冰川 ICESat-2激光光子 

分 类 号：P343.6[天文地球—水文科学] P216[天文地球—地球物理学]