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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369天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,本文通过对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,本文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,二者在相对积累特征上基本一致。
Satellite altimetry technique is the main method to study the elevation change and material balance of the ice surface. Compared to traditional altimeter, CryoSat-2 can not only provide more intensive coverage of the track, but also improve the measurement accuracy of the edge of the Antarctic. However, the 369-day revisit cycle also makes the conventional time-series analysis based on the cross-track algorithm no longer applicable. Based on the analysis of the trajectory characteristics of CryoSat-2, this paper presents a model of ice surface elevation change based on the near-duplicate orbit. For CryoSat-2 data preprocessing, the gross error rejecting method based on the surface model is adopted in this paper. Based on the collaborative analysis of EnviSat and CryoSat-2, the systematic trend of backscattering energy in CryoSat-2 was corrected. Using the CryoSat-2 data from January 2012 to May 2014, the changes of ice surface elevation along the PANDA section of the East Pole were studied. The experimental results show that the trend of elevation along the survey line is 0.017 ± 0.009m / a. This conclusion is consistent with the average accumulation rate of other scholars extracting the corresponding river basins. But its distribution is not uniform, local effect is obvious. Compared with the measured results of the survey line, the two are basically the same in the relative accumulation characteristics.