利用CryoSat-2测高数据研究东南极PANDA断面考察沿线高程变化

Elevation Change Along the Expedition Route in PANDA Transection of Antarctica from Cryosat-2

卫星测高技术是研究两极冰面高程变化和物质平衡状态的主要手段。相对于传统高度计,CryoSat-2不仅能够提供更加密集的轨道覆盖,同时也提高了南极边缘地区的测量精度。但369d的重访周期也使得传统的基于交叉轨道算法的时序分析不再适用,通过对CryoSat-2轨迹特征的分析,提出了基于近重复轨道的冰面高程变化模型。针对CryoSat-2数据预处理,采用基于地表模型的粗差剔除方法进行了粗差剔除,并基于EnviSat与CryoSat-2的协同分析,对CryoSat-2中的后向散射能量进行了系统变化趋势改正。利用2012-01~2014-05的CryoSat-2数据,对东南极PANDA断面考察沿线冰面高程变化进行了研究。实验结果表明,整个考察沿线高程变化趋势为0.017±0.009m/a。该结论与其他学者提取相应流域的平均积累率相一致。但其分布不均匀,局部效应明显。通过与考察线路实测结果对比,两者在相对积累特征上基本一致。

Satellite radar altimetry has been widely used to investigate the elevation change and mass balance in the polar region.Compared with traditional radar altimeters,CryoSat can not only provide a denser network of ground tracks but also higher measuring accuracy.However,the long orbit cycle（369days）of CryoSat is less suited to the conventional cross-over technique that has been applied to longer time series.In this paper,a new method called the near repeat track is proposed and the related data preprocessing of Gross Error Elimination and Backscatter correction are also introduced,based on the data characteristics and the collaborative analysis between CryoSat and EnviSat.Using these methods,the elevation change in the PANDA transection of Antarctica from 2012 to 2014was extracted and analysed.The result shows an ascending trend of 0.017±0.009m/a that agrees well with the result of other research along the inspection route in the PANDA transection.However,the accumulation of distribution is not uniform.To check the results,the elevation change as presented in this paper is compared with the field measurement data,and the same trend was obtained.