Abstract:
Polarimetric phase-sensitive radar measurements were collected at the Western Antarctic Ice Sheet (WAIS) Divide on the 25th and 26th December 2019. The measurements were conducted at 10 sites along a 6 km-long transect ~5-10 km northeast of the location of the WAIS Divide Deep Ice Core. At each site, a suite of four quadrature (quad-) polarimetric measurements were collected using an autonomous phase-sensitive radio echo sounder (ApRES) in a single-input single-output (SISO) configuration.
The study is part of the Thwaites Interdisciplinary Margin Evolution (TIME) project of the International Thwaites Glacier Collaboration (ITGC), and is a collaboration between the United States National Science Foundation (NSF) and the United Kingdom Natural Environment Research Council (NERC). It was funded by UK Natural Environment Research Council (NERC) research grant NE/S006788/1 and USA National Science Foundation (NSF) research grant 1739027.
Keywords:
ApRES, ITGC, anisotropy, fabric, radar, radar polarimetry
Young, T., & Dawson, E. (2021). Quad-polarimetric ApRES measurements along a 6 km-long transect at the WAIS Divide, December 2019 (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/ba1caf7a-d4e0-4671-972a-e567a25ccd2c
| Access Constraints: | No restrictions apply. |
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| Use Constraints: | Data supplied under Open Government Licence v3.0 http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/. |
| Creation Date: | 2021-05-05 |
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| Dataset Progress: | Complete |
| Dataset Language: | English |
| ISO Topic Categories: |
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| Parameters: |
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| Personnel: | |
| Name | UK Polar Data Centre |
| Role(s) | Metadata Author |
| Organisation | British Antarctic Survey |
| Name | Tun Jan Young |
| Role(s) | Investigator, Technical Contact |
| Organisation | Scott Polar Research Institute, University of Cambridge |
| Name | Eliza J Dawson |
| Role(s) | Investigator |
| Organisation | Stanford University |
| Parent Dataset: | N/A |
| Reference: | Young, T. J., Martín, C., Christoffersen, P., Schroeder, D. M., Tulaczyk, S. M., and Dawson, E. J.: Rapid and accurate polarimetric radar measurements of ice crystal fabric orientation at the Western Antarctic Ice Sheet (WAIS) Divide ice core site, The Cryosphere, 15, 4117-4133, https://doi.org/10.5194/tc-15-4117-2021, 2021. | |
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| Quality: | The coarse-range (amplitude-derived) vertical (depth) resolution of the ApRES is 0.54 m. The azimuthal accuracy is unknown and is mainly the result of human error in alignment of antennas. A nominal azimuthal error of ±8° is assigned. The data included in this dataset are raw data and are entirely unprocessed. | |
| Lineage: | For each site, a suite of four quadrature (quad-) polarimetric measurements were collected using an autonomous phase-sensitive radio echo sounder (ApRES) in a single-input single-output configuration. Each measurement consisted of 100 chirps, with each chirp consisting of a linear sweep from 200 to 400 MHz over the course of 1 second, corresponding to a centre frequency of 300 MHz over a bandwidth of 200 MHz. For each measurement, two open-structure antennas (1 transmitting, 1 receiving) were positioned with their centres 8.00 m apart in combinations of four orthogonal antenna orientations, where antennas were positioned in either a horizontal (h) or vertical (v) alignment with respect to the antenna's electric plane. The four orientation combinations are therefore hh, hv, vv, and vh. Measurements were conducted sequentially, and each antenna pair orientation was established by rotating one or both antennas by 90° with respect to their previous orientations while keeping the position of each antenna centre constant. The antenna plane (parallel to the h orientation; 110°) was oriented perpendicular to the transect line (20°). The complete data collection period at each site, from the start of setup to the conclusion of packing, was ~30 minutes. | |
| Temporal Coverage: | |
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| Start Date | 2019-12-25 |
| End Date | 2019-12-26 |
| Spatial Coverage: | |
| Latitude | |
| Southernmost | -79.43485 |
| Northernmost | -79.38234 |
| Longitude | |
| Westernmost | -111.9945 |
| Easternmost | -111.8901 |
| Altitude | |
| Min Altitude | 1780 m |
| Max Altitude | 1792 m |
| Depth | |
| Min Depth | N/A |
| Max Depth | N/A |
| Location: | |
| Location | Antarctica |
| Detailed Location | West Antarctic Ice Sheet Divide |
| Sensor(s): |
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| Data Collection: | Data collection: SISO autonomous phase-sensitive radio-echo sounder (version dated to 20170925) with 2x open-structure ("skeleton-slot") antennas. Data analysis and processing: MATLAB. |
| Distribution: | |
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| Distribution Media | Online Internet (HTTP) |
| Distribution Size | 306.6 MB |
| Distribution Format | netCDF |
| Fees | N/A |
| Data Storage: | 4x10 polarimetric radar data files (.nc). 1x table of metadata (.csv). 1x README file of supporting metadata (.txt). 1x photograph showing example experiment setup (.jpg). |