Cryosat-2测高数据的太湖水位监测与变化分析  

Monitoring and variation analysis of water level in Lake Taihu based on Cryosat-2 altimeter data

作　　者：常翔宇 蔡宇[1] 夏文韬 柯长青[1] CHANG Xiangyu;CAI Yu;XIA Wentao;KE Changqing(School of Geography and Ocean Sciences,Nanjing University,Nanjing 210023,China)

机构地区：[1]南京大学地理与海洋科学学院,南京210023

出　　处：《测绘科学》2020年第10期85-91,共7页Science of Surveying and Mapping

基　　金：江苏省基础研究计划(自然科学基金)项目(BK20180343)。

摘　　要：针对传统的通过水位站监测湖泊水位变化受自然条件和时空等因素的影响以及卫星测高技术的发展,该文提出了利用Cryosat-2测高数据对内陆湖泊水位变化进行研究。以太湖为例分析2011年1月—2014年12月的水位变化,并应用水位实测数据对Level-2 GDR数据所采用的3种波形重跟踪算法提取的湖面高进行精度评价以及季节性变化的对比。结果表明,4年来太湖平均水位变化为0.283 m,测高结果与实测数据变化基本一致,最高值均出现在2011年9月,利用卫星测高数据监测湖泊水位变化可信度较高;对于GDR产品中的3种重跟踪算法,Refined OCOG算法更适合水位变化的提取,有最高的相关系数(0.543)、较低的均方根误差(1.282 m)和最低平均绝对误差(0.260 m);太湖的秋季水位最高,夏季其次,冬季再次,春季最低,且春夏两季水位变化提取的均方根误差最低可达到0.215 m和0.067 m。Accroding to the fact that traditional monitoring of lake water level change through water level observation station is affected by natural conditions,time and space,and the development of satellite altimetry technology,this paper presented using the Cryosat-2 altimetry data to study the change of lake water level in inland lakes. Taking Lake Taihu as an example,this paper analyzed the variation of water level from January 2011 to December 2014 and used in-situ gauging data to evaluate the accuracy of lake surface height extracted from Level-2 GDR data by three retracking algorithms and then compared the seasonal changes. The results indicated that the lake level variation obtained from satellite altimeter data were reliable,and the average water level variation of Lake Taihu in 4 years was 0.283 m. The results of altimetry were basically consistent with the in-situ gauging data,and the highest values both found in September 2011. For the three re-tracking algorithms in GDR products,the Refined OCOG algorithm was more suitable for the extraction of water level variation,with the highest correlation coefficient(0.543),lower root mean square error(1.282 m) and the lowest mean absolute error(0.260 m). The water level of Lake Taihu was the highest in autumn,the next in summer,the third in winter and the lowest in spring,while the root mean square error of water level variation in spring and summer was 0.215 m and 0.067 m respectively.

关 键 词：卫星测高 Cryosat-2 重跟踪 湖泊水位变化 太湖 

分 类 号：P237[天文地球—摄影测量与遥感]