The application of millimetre-wave radar to the study of the cryosphere
This thesis develops the technique of millimetre-wave radar at 94 GHz for close-range remote sensing of glaciers and terrestrial snow cover (the cryosphere). The capabilities of 94 GHz radar for cryosphere mapping are demonstrated using the 2ⁿᵈ generation All-weather Volcano Topography Imaging Senso...
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Format: | Doctoral or Postdoctoral Thesis |
Language: | English |
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The University of St Andrews
2023
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Online Access: | http://hdl.handle.net/10023/27235 https://doi.org/10.17630/sta/360 |
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ftstandrewserep:oai:research-repository.st-andrews.ac.uk:10023/27235 2023-07-02T03:31:36+02:00 The application of millimetre-wave radar to the study of the cryosphere Harcourt, William David Robertson, Duncan Alexander Macfarlane, David G. Rea, Brice R. Spagnolo, Matteo Benn, Douglas I. Engineering and Physical Sciences Research Council (EPSRC) Scottish Alliance for Geoscience, Environment and Society (SAGES) xl, 279 p. 2023-03-21T15:26:44Z application/pdf application/zip http://hdl.handle.net/10023/27235 https://doi.org/10.17630/sta/360 en eng The University of St Andrews http://hdl.handle.net/10023/27235 https://doi.org/10.17630/sta/360 EP/R513337/1 Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/ 2024-01-18 Restricted in accordance with University regulations. Restricted until 18th January 2024 Radar Close range sensing Remote sensing Glaciology Snow dynamics Arctic Point clouds Thesis Doctoral PhD Doctor of Philosophy 2023 ftstandrewserep https://doi.org/10.17630/sta/360 2023-06-13T18:27:34Z This thesis develops the technique of millimetre-wave radar at 94 GHz for close-range remote sensing of glaciers and terrestrial snow cover (the cryosphere). The capabilities of 94 GHz radar for cryosphere mapping are demonstrated using the 2ⁿᵈ generation All-weather Volcano Topography Imaging Sensor (AVTIS2), which maps 3D terrain from real-beam scanning. AVTIS2 acquires 3D point clouds of terrain and a comparison to co-located high density point clouds derived from Terrestrial Laser Scanner (TLS) data showed that AVTIS2 point cloud uncertainties were 1.5 m at 1.5 km and 3 m at 3 km. These values are smaller than other close-range radar systems used to map cryospheric terrain in 3D. Next, the distribution of Normalised Radar Cross Section (σ⁰) values over glacier ice at 94 GHz was found to be −17.0 < σ⁰ < −3.4; σ⁰ₘₑₐₙ = −9.9 dB and followed a log-normal distribution. These values are comparable to other terrain types at 94 GHz such as refrozen snow, wet snow and wet soil, hence glacier surfaces were found to be suitable targets for terrain mapping at 94 GHz. These fundamental results were used to apply the AVTIS2 94 GHz radar for monitoring snow cover and glacier calving. Field trials in Scotland showed that the transition of wet snow to a refrozen snowpack in response to reductions in air temperature could be detected from changes in 94 GHz σ⁰. Snow hazard features could also be identified, such as post-avalanche debris accumulations which manifest as localised increases in radar backscatter. Next, 3D AVTIS2 data was used to quantify glacier calving rates at the Hansbreen tidewater glacier in Svalbard. A time series of ice cliff morphology derived from the AVTIS2 3D data sets exposed the role of melt undercutting and demonstrated the critical role of the ocean on calving processes in Svalbard. The high accuracy 3D data acquired from AVTIS2 and the sensitivity of radar backscatter to surface changes has demonstrated the unique capabilities of 94 GHz radar for cryosphere mapping, paving the way forward for ... Doctoral or Postdoctoral Thesis Arctic glacier Svalbard Tidewater University of St Andrews: Digital Research Repository Arctic Hansbreen ENVELOPE(15.650,15.650,77.075,77.075) Svalbard |
institution |
Open Polar |
collection |
University of St Andrews: Digital Research Repository |
op_collection_id |
ftstandrewserep |
language |
English |
topic |
Radar Close range sensing Remote sensing Glaciology Snow dynamics Arctic Point clouds |
spellingShingle |
Radar Close range sensing Remote sensing Glaciology Snow dynamics Arctic Point clouds Harcourt, William David The application of millimetre-wave radar to the study of the cryosphere |
topic_facet |
Radar Close range sensing Remote sensing Glaciology Snow dynamics Arctic Point clouds |
description |
This thesis develops the technique of millimetre-wave radar at 94 GHz for close-range remote sensing of glaciers and terrestrial snow cover (the cryosphere). The capabilities of 94 GHz radar for cryosphere mapping are demonstrated using the 2ⁿᵈ generation All-weather Volcano Topography Imaging Sensor (AVTIS2), which maps 3D terrain from real-beam scanning. AVTIS2 acquires 3D point clouds of terrain and a comparison to co-located high density point clouds derived from Terrestrial Laser Scanner (TLS) data showed that AVTIS2 point cloud uncertainties were 1.5 m at 1.5 km and 3 m at 3 km. These values are smaller than other close-range radar systems used to map cryospheric terrain in 3D. Next, the distribution of Normalised Radar Cross Section (σ⁰) values over glacier ice at 94 GHz was found to be −17.0 < σ⁰ < −3.4; σ⁰ₘₑₐₙ = −9.9 dB and followed a log-normal distribution. These values are comparable to other terrain types at 94 GHz such as refrozen snow, wet snow and wet soil, hence glacier surfaces were found to be suitable targets for terrain mapping at 94 GHz. These fundamental results were used to apply the AVTIS2 94 GHz radar for monitoring snow cover and glacier calving. Field trials in Scotland showed that the transition of wet snow to a refrozen snowpack in response to reductions in air temperature could be detected from changes in 94 GHz σ⁰. Snow hazard features could also be identified, such as post-avalanche debris accumulations which manifest as localised increases in radar backscatter. Next, 3D AVTIS2 data was used to quantify glacier calving rates at the Hansbreen tidewater glacier in Svalbard. A time series of ice cliff morphology derived from the AVTIS2 3D data sets exposed the role of melt undercutting and demonstrated the critical role of the ocean on calving processes in Svalbard. The high accuracy 3D data acquired from AVTIS2 and the sensitivity of radar backscatter to surface changes has demonstrated the unique capabilities of 94 GHz radar for cryosphere mapping, paving the way forward for ... |
author2 |
Robertson, Duncan Alexander Macfarlane, David G. Rea, Brice R. Spagnolo, Matteo Benn, Douglas I. Engineering and Physical Sciences Research Council (EPSRC) Scottish Alliance for Geoscience, Environment and Society (SAGES) |
format |
Doctoral or Postdoctoral Thesis |
author |
Harcourt, William David |
author_facet |
Harcourt, William David |
author_sort |
Harcourt, William David |
title |
The application of millimetre-wave radar to the study of the cryosphere |
title_short |
The application of millimetre-wave radar to the study of the cryosphere |
title_full |
The application of millimetre-wave radar to the study of the cryosphere |
title_fullStr |
The application of millimetre-wave radar to the study of the cryosphere |
title_full_unstemmed |
The application of millimetre-wave radar to the study of the cryosphere |
title_sort |
application of millimetre-wave radar to the study of the cryosphere |
publisher |
The University of St Andrews |
publishDate |
2023 |
url |
http://hdl.handle.net/10023/27235 https://doi.org/10.17630/sta/360 |
op_coverage |
xl, 279 p. |
long_lat |
ENVELOPE(15.650,15.650,77.075,77.075) |
geographic |
Arctic Hansbreen Svalbard |
geographic_facet |
Arctic Hansbreen Svalbard |
genre |
Arctic glacier Svalbard Tidewater |
genre_facet |
Arctic glacier Svalbard Tidewater |
op_relation |
http://hdl.handle.net/10023/27235 https://doi.org/10.17630/sta/360 EP/R513337/1 |
op_rights |
Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/ 2024-01-18 Restricted in accordance with University regulations. Restricted until 18th January 2024 |
op_doi |
https://doi.org/10.17630/sta/360 |
_version_ |
1770270963481444352 |