Empirical removal of tides and inverse barometer effect on DInSAR from double DInSAR and a regional climate model
Glaude, Q.; Amory, C.; Berger, S.; Derauw, D.; Pattyn, F.; Barbier, C.; Orban, A. (2020). Empirical removal of tides and inverse barometer effect on DInSAR from double DInSAR and a regional climate model. IEEE J. Sel. Top. Appl. Earth Observ. Remote Sens. 13: 4085-4094. https://hdl.handle.net/10.1109/JSTARS.2020.3008497 In: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing. IEEE: Piscataway. ISSN 1939-1404; e-ISSN 2151-1535, more |   |
| Author keywords | Antarctica; differential synthetic aperture radar (SAR) interferometry (DInSAR); double DInSAR (DDInSAR); ice shelf; inverse barometer effect(IBE); tides |
| Authors | | Top | | - Pattyn, F., more
- Barbier, C.
- Orban, A.
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| Abstract | 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. |
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