Multi-channel and multi-polarization radar measurements around the NEEM site
This work is distributed under the Creative Commons Attribution 4.0 License. Ice properties inferred from multi-polarization measurements, such as birefringence and crystal orientation fabric (COF), can provide insight into ice strain, viscosity, and ice flow. In 2008, the Center for Remote Sensing...
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Online Access: | http://hdl.handle.net/1808/29819 https://doi.org/10.5194/tc-12-2689-2018 |
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ftunivkansas:oai:kuscholarworks.ku.edu:1808/29819 2023-05-15T15:53:45+02:00 Multi-channel and multi-polarization radar measurements around the NEEM site Li, Jilu Vélez González, Jose A. Leuschen, Carl Harish, Ayyangar Gogineni, Prasad Montagnat, Maurine Weikusat, Ilka Rodriguez-Morales, Fernando Paden, John 2019-11-25T23:24:23Z http://hdl.handle.net/1808/29819 https://doi.org/10.5194/tc-12-2689-2018 unknown European Geosciences Union Li, J., Vélez González, J. A., Leuschen, C., Harish, A., Gogineni, P., Montagnat, M., Weikusat, I., Rodriguez-Morales, F., and Paden, J.: Multi-channel and multi-polarization radar measurements around the NEEM site, The Cryosphere, 12, 2689–2705, https://doi.org/10.5194/tc-12-2689-2018, 2018. http://hdl.handle.net/1808/29819 doi:10.5194/tc-12-2689-2018 orcid:0000-0002-3023-6036 © Author(s) 2018. This work is distributed under the Creative Commons Attribution 4.0 License. http://creativecommons.org/licenses/by/4.0/ openAccess CC-BY Article 2019 ftunivkansas https://doi.org/10.5194/tc-12-2689-2018 2022-08-26T13:25:02Z This work is distributed under the Creative Commons Attribution 4.0 License. Ice properties inferred from multi-polarization measurements, such as birefringence and crystal orientation fabric (COF), can provide insight into ice strain, viscosity, and ice flow. In 2008, the Center for Remote Sensing of Ice Sheets (CReSIS) used a ground-based VHF (very high frequency) radar to take multi-channel and multi-polarization measurements around the NEEM (North Greenland Eemian Ice Drilling) site. The system operated with 30 MHz bandwidth at a center frequency of 150 MHz. This paper describes the radar system, antenna configurations, data collection, and processing and analysis of this data set. Within the framework derived from uniaxial ice crystal model, we found that ice birefringence dominates the power variation patterns of co-polarization and cross-polarization measurements in the area of 100 km2 around the ice core site. The phase shift between ordinary and extraordinary waves increases nonlinearly with depth. The ice optic axis lies in planes that are close to the vertical plane and perpendicular or parallel to the ice divide depending on depth. The ice optic axis has an average tilt angle of about 11.6° vertically, and its plane may rotate either clockwise or counterclockwise by about 10° across the 100 km2 area, and at a specific location the plane may rotate slightly counterclockwise as depth increases. Comparisons between the radar observations, simulations, and ice core fabric data are in very good agreement. We calculated the effective colatitude at different depths by using azimuth and colatitude measurements of the c axis of ice crystals. We obtained an average effective c axis tilt angle of 9.6° from the vertical axis, very comparable to the average optic axis tilt angle estimated from radar polarization measurements. The comparisons give us confidence in applying this polarimetric radio echo sounding technique to infer profiles of ice fabric in locations where there are no ice core measurements. Article in Journal/Newspaper Center for Remote Sensing of Ice Sheets (CReSIS) Greenland ice core North Greenland The Cryosphere The University of Kansas: KU ScholarWorks Greenland The Cryosphere 12 8 2689 2705 |
institution |
Open Polar |
collection |
The University of Kansas: KU ScholarWorks |
op_collection_id |
ftunivkansas |
language |
unknown |
description |
This work is distributed under the Creative Commons Attribution 4.0 License. Ice properties inferred from multi-polarization measurements, such as birefringence and crystal orientation fabric (COF), can provide insight into ice strain, viscosity, and ice flow. In 2008, the Center for Remote Sensing of Ice Sheets (CReSIS) used a ground-based VHF (very high frequency) radar to take multi-channel and multi-polarization measurements around the NEEM (North Greenland Eemian Ice Drilling) site. The system operated with 30 MHz bandwidth at a center frequency of 150 MHz. This paper describes the radar system, antenna configurations, data collection, and processing and analysis of this data set. Within the framework derived from uniaxial ice crystal model, we found that ice birefringence dominates the power variation patterns of co-polarization and cross-polarization measurements in the area of 100 km2 around the ice core site. The phase shift between ordinary and extraordinary waves increases nonlinearly with depth. The ice optic axis lies in planes that are close to the vertical plane and perpendicular or parallel to the ice divide depending on depth. The ice optic axis has an average tilt angle of about 11.6° vertically, and its plane may rotate either clockwise or counterclockwise by about 10° across the 100 km2 area, and at a specific location the plane may rotate slightly counterclockwise as depth increases. Comparisons between the radar observations, simulations, and ice core fabric data are in very good agreement. We calculated the effective colatitude at different depths by using azimuth and colatitude measurements of the c axis of ice crystals. We obtained an average effective c axis tilt angle of 9.6° from the vertical axis, very comparable to the average optic axis tilt angle estimated from radar polarization measurements. The comparisons give us confidence in applying this polarimetric radio echo sounding technique to infer profiles of ice fabric in locations where there are no ice core measurements. |
format |
Article in Journal/Newspaper |
author |
Li, Jilu Vélez González, Jose A. Leuschen, Carl Harish, Ayyangar Gogineni, Prasad Montagnat, Maurine Weikusat, Ilka Rodriguez-Morales, Fernando Paden, John |
spellingShingle |
Li, Jilu Vélez González, Jose A. Leuschen, Carl Harish, Ayyangar Gogineni, Prasad Montagnat, Maurine Weikusat, Ilka Rodriguez-Morales, Fernando Paden, John Multi-channel and multi-polarization radar measurements around the NEEM site |
author_facet |
Li, Jilu Vélez González, Jose A. Leuschen, Carl Harish, Ayyangar Gogineni, Prasad Montagnat, Maurine Weikusat, Ilka Rodriguez-Morales, Fernando Paden, John |
author_sort |
Li, Jilu |
title |
Multi-channel and multi-polarization radar measurements around the NEEM site |
title_short |
Multi-channel and multi-polarization radar measurements around the NEEM site |
title_full |
Multi-channel and multi-polarization radar measurements around the NEEM site |
title_fullStr |
Multi-channel and multi-polarization radar measurements around the NEEM site |
title_full_unstemmed |
Multi-channel and multi-polarization radar measurements around the NEEM site |
title_sort |
multi-channel and multi-polarization radar measurements around the neem site |
publisher |
European Geosciences Union |
publishDate |
2019 |
url |
http://hdl.handle.net/1808/29819 https://doi.org/10.5194/tc-12-2689-2018 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Center for Remote Sensing of Ice Sheets (CReSIS) Greenland ice core North Greenland The Cryosphere |
genre_facet |
Center for Remote Sensing of Ice Sheets (CReSIS) Greenland ice core North Greenland The Cryosphere |
op_relation |
Li, J., Vélez González, J. A., Leuschen, C., Harish, A., Gogineni, P., Montagnat, M., Weikusat, I., Rodriguez-Morales, F., and Paden, J.: Multi-channel and multi-polarization radar measurements around the NEEM site, The Cryosphere, 12, 2689–2705, https://doi.org/10.5194/tc-12-2689-2018, 2018. http://hdl.handle.net/1808/29819 doi:10.5194/tc-12-2689-2018 orcid:0000-0002-3023-6036 |
op_rights |
© Author(s) 2018. This work is distributed under the Creative Commons Attribution 4.0 License. http://creativecommons.org/licenses/by/4.0/ openAccess |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.5194/tc-12-2689-2018 |
container_title |
The Cryosphere |
container_volume |
12 |
container_issue |
8 |
container_start_page |
2689 |
op_container_end_page |
2705 |
_version_ |
1766388933902467072 |