Ice shelves-the floating extensions of the Antarctic ice sheet-regulate the Antarctic contribution to sea-level rise by restraining the grounded ice flowing from upstream. Therefore, ice-shelf change (e.g., ice-shelf thinning) results in accelerated ice discharge into the ocean, which has a direct effect on sea level. Studying ice-shelf velocity allows the monitoring of the ice shelves' stability and evolution. Differential synthetic aperture radar interferometry (DInSAR) is a common technique from which highly accurate velocity maps can be inferred at high resolution. Because ice shelves are afloat, small sea-level changes-i.e., ocean tides and varying atmospheric pressure (aka inverse barometer effect) lead to vertical displacements. If not accounted for in the interferometric process, these effects will induce a strong bias in the horizontal velocity estimation. In this article, we present an empirical DInSAR correction technique from geophysical models and double DInSAR, with a study on its variance propagation. The method is developed to be used at large coverage on short timescales, essential for the near-continuous monitoring of rapidly changing areas on polar ice sheets. We used Sentinel-1 SAR acquisitions in interferometric wide and extra -wide swath modes. The vertical interferometric bias is estimated using a regional climate model (MAR) and a tide model (CATS2008). The study area is located on the Roi Baudouin Ice Shelf in Dronning Maud Land, East Antarctica. Results show a major decrease (67 m·a -1 ) in the vertical-induced displacement bias.

中文翻译：

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双DInSAR和区域气候模型对DInSAR的潮汐和反气压效应的实证去除


冰架——南极冰盖的漂浮延伸部分——通过抑制上游的接地冰流动来调节南极对海平面上升的贡献。因此，冰架变化（例如冰架变薄）会导致冰加速流入海洋，从而对海平面产生直接影响。研究冰架速度可以监测冰架的稳定性和演变。差分合成孔径雷达干涉测量 (DInSAR) 是一种常用技术，可以从中推断出高分辨率的高精度速度图。由于冰架是漂浮的，海平面的微小变化，即海洋潮汐和变化的大气压力（又名逆气压计效应）会导致垂直位移。如果在干涉过程中不考虑这些影响，这些影响将在水平速度估计中引起强烈的偏差。在本文中，我们提出了一种基于地球物理模型和双 DInSAR 的经验 DInSAR 校正技术，并对其方差传播进行了研究。该方法被开发用于短时间尺度的大覆盖范围，这对于近乎连续地监测极地冰盖上快速变化的区域至关重要。我们在干涉宽和超宽测绘带模式下使用了 Sentinel-1 SAR 采集。使用区域气候模型（MAR）和潮汐模型（CATS2008）估计垂直干涉偏差。研究区位于东南极洲 Dronning Maud 地的 Roi Baudouin 冰架上。结果显示垂直引起的位移偏差显着减小（67 m·a -1 ）。