McMillan, MJ orcid.org/0000-0002-5113-0177, Shepherd, A orcid.org/0000-0002-4914-1299, Muir, A et al. (3 more authors) (2018) Assessment of CryoSat-2 interferometric and non-interferometric SAR altimetry over ice sheets. Advances in Space Research, 62 (6). pp. 1281-1291. ISSN 0273-1177
Abstract
The launch of CryoSat-2 heralded a new era of interferometric Synthetic Aperture Radar altimetry over the Polar Ice Sheets. The mission’s novel SAR interferometric (SARIn) mode of operation has enabled monitoring of rapidly changing coastal regions, which had been challenging for previous low resolution altimeters. Given the growing requirement to continue the 25-year altimeter record, there is now a need to assess the differences between existing SAR and SARIn altimeter datasets, with a view to understanding the impact on ice sheet retrievals of the different radar hardware and processing methodologies. Uniquely, CryoSat-2 data can be processed both with and without interferometric information, offering the opportunity to directly compare the SAR and SARIn products generated by the current ground segment. Here, we provide a first comparison of these Level-2 datasets, and evaluate their capacity to measure ice sheet elevation and elevation change. We find that the current interferometric product has substantially improved precision, accuracy and coverage compared to its non-interferometric counterpart, yielding a ∼35% improvement in the root-mean-square-difference (RMSD) of elevations recorded at orbital cross-overs, and a ∼30% lower RMSD of elevation rates relative to Operation IceBridge airborne altimeter measurements. This analysis demonstrates the value that the interferometer adds to the current CryoSat-2 configuration, and highlights the importance for non-interferometric SAR Level-2 processing of the auxiliary data used to identify the location of the echoing point. These results provide a benchmark of the relative performance of the Level-2 interferometric and non-interferometric products currently produced by the ground segment, which will help to inform the design and implementation of a future polar radar altimeter mission.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2017, COSPAR. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). |
Keywords: | CryoSat-2; SAR altimetry; Geodesy; Ice sheets; Satellite radar interferometry; Antarctica |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Inst for Climate & Atmos Science (ICAS) (Leeds) |
Funding Information: | Funder Grant number NERC No External Reference European Space Agency UL_ESA_CS_FO European Space Agency No External Ref |
Depositing User: | Symplectic Publications |
Date Deposited: | 13 Dec 2017 16:39 |
Last Modified: | 29 Aug 2018 01:34 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.asr.2017.11.036 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:125161 |