Mapping ice-shelf flow with interferometric synthetic aperture radar stacking
Mapping ice-shelf flow with interferometric synthetic aperture radar stacking
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DOI：
10.3189/2012jog11j072
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发表时间：
2012
影响因子：
3.4
通讯作者：
M. McMillan;A. Shepherd;N. Gourmelen;Jeong-Won Park;P. Nienow;E. Rinne;A. Leeson
中科院分区：
文献类型：
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作者：
M. McMillan;A. Shepherd;N. Gourmelen;Jeong-Won Park;P. Nienow;E. Rinne;A. Leeson
干涉合成孔径雷达（InSAR）对冰架流的观测包含海潮和大气压信号。可以采用基于模型的校正方法，但该方法受模型精度的限制，而模型精度在偏远地区是不确定的。本文描述了一种独立于潮汐和大气压模式预测的二维冰架流动矢量的方法，该方法通过叠加南极西部多特森冰架的常规和多孔径InSAR （MAI）观测数据。通过这种方式，我们合成了一个较长的观测周期，相对于快速变化的（潮汐和大气压力）信号和噪声，它增强了长周期（流量）位移信号。我们估计与速度场的每个分量相关的误差为~22ma -1，如果有更多的图像可以堆叠，则可以进一步降低误差。随着即将发射的几个卫星任务，提供了定期短重复SAR采集的前景，本研究表明，叠加可以改善冰架流速的估计。
Interferometric synthetic aperture radar (InSAR) observations of ice-shelf flow contain ocean-tide and atmospheric-pressure signals. A model-based correction can be applied, but this method is limited by its dependency upon model accuracy, which in remote regions can be uncertain. Here we describe a method to determine two-dimensional ice-shelf flow vectors independently of model predictions of tide and atmospheric pressure, by stacking conventional and multiple aperture InSAR (MAI) observations of the Dotson Ice Shelf, West Antarctica. In this way we synthesize a longer observation period, which enhances long-period (flow) displacement signals, relative to rapidly varying (tide and atmospheric pressure) signals and noise.We estimate the error associated with each component of the velocity field to be ~22ma -1, which could be further reduced if more images were available to stack. With the upcoming launch of several satellite missions, offering the prospect of regular short-repeat SAR acquisitions, this study demonstrates that stacking can improve estimates of ice-shelf flow velocity.