Depth-dependent artifacts resulting from ApRES signal clipping
Several autonomous phase-sensitive radio-echo sounders (ApRES) were deployed at Greenland glaciers to investigate ice deformation. Different attenuation settings were tested and it was observed that, in the presence of clipping of the deramped ApRES signal, each setting produced a different result....
Published in: | Annals of Glaciology |
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Language: | English |
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Cambridge University Press
2020
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Online Access: | http://nora.nerc.ac.uk/id/eprint/528026/ https://nora.nerc.ac.uk/id/eprint/528026/1/depthdependent_artifacts_resulting_from_apres_signal_clipping.pdf https://www.cambridge.org/core/journals/annals-of-glaciology/article/depthdependent-artifacts-resulting-from-apres-signal-clipping/74C8B78B415646A16B15CF418749D9E0 |
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ftnerc:oai:nora.nerc.ac.uk:528026 2024-02-11T09:55:39+01:00 Depth-dependent artifacts resulting from ApRES signal clipping Vaňková, Irena Nicholls, Keith W. Xie, Surui Parizek, Byron R. Voytenko, Denis Holland, David M. 2020-07-28 text http://nora.nerc.ac.uk/id/eprint/528026/ https://nora.nerc.ac.uk/id/eprint/528026/1/depthdependent_artifacts_resulting_from_apres_signal_clipping.pdf https://www.cambridge.org/core/journals/annals-of-glaciology/article/depthdependent-artifacts-resulting-from-apres-signal-clipping/74C8B78B415646A16B15CF418749D9E0 en eng Cambridge University Press https://nora.nerc.ac.uk/id/eprint/528026/1/depthdependent_artifacts_resulting_from_apres_signal_clipping.pdf Vaňková, Irena orcid:0000-0003-4351-3781 Nicholls, Keith W. orcid:0000-0002-2188-4509 Xie, Surui; Parizek, Byron R.; Voytenko, Denis; Holland, David M. 2020 Depth-dependent artifacts resulting from ApRES signal clipping. Annals of Glaciology, 61 (81). 108-113. https://doi.org/10.1017/aog.2020.56 <https://doi.org/10.1017/aog.2020.56> cc_by_4 Publication - Article PeerReviewed 2020 ftnerc https://doi.org/10.1017/aog.2020.56 2024-01-19T00:03:17Z Several autonomous phase-sensitive radio-echo sounders (ApRES) were deployed at Greenland glaciers to investigate ice deformation. Different attenuation settings were tested and it was observed that, in the presence of clipping of the deramped ApRES signal, each setting produced a different result. Specifically, higher levels of clipping associated with lower attenuation produced an apparent linear increase of diurnal vertical cumulative displacement with depth, and obscured the visibility of the basal reflector in the return amplitude. An example with a synthetic deramped signal confirmed that these types of artifacts result from the introduction of harmonics from square-wave-like features introduced by clipping. Apparent linear increase of vertical displacement with depth occurs when the vertical position of a near-surface internal reflector changes in time. Artifacts in the return amplitude may obscure returns from internal reflectors and the basal reflector, making it difficult to detect thickness evolution of the ice and to correctly estimate vertical velocities. Variations in surface melt during ApRES deployments can substantially modulate the received signal strength on short timescales, and we therefore recommend using higher attenuator settings for deployments in such locations. Article in Journal/Newspaper Annals of Glaciology Greenland Natural Environment Research Council: NERC Open Research Archive Greenland Annals of Glaciology 61 81 108 113 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
English |
description |
Several autonomous phase-sensitive radio-echo sounders (ApRES) were deployed at Greenland glaciers to investigate ice deformation. Different attenuation settings were tested and it was observed that, in the presence of clipping of the deramped ApRES signal, each setting produced a different result. Specifically, higher levels of clipping associated with lower attenuation produced an apparent linear increase of diurnal vertical cumulative displacement with depth, and obscured the visibility of the basal reflector in the return amplitude. An example with a synthetic deramped signal confirmed that these types of artifacts result from the introduction of harmonics from square-wave-like features introduced by clipping. Apparent linear increase of vertical displacement with depth occurs when the vertical position of a near-surface internal reflector changes in time. Artifacts in the return amplitude may obscure returns from internal reflectors and the basal reflector, making it difficult to detect thickness evolution of the ice and to correctly estimate vertical velocities. Variations in surface melt during ApRES deployments can substantially modulate the received signal strength on short timescales, and we therefore recommend using higher attenuator settings for deployments in such locations. |
format |
Article in Journal/Newspaper |
author |
Vaňková, Irena Nicholls, Keith W. Xie, Surui Parizek, Byron R. Voytenko, Denis Holland, David M. |
spellingShingle |
Vaňková, Irena Nicholls, Keith W. Xie, Surui Parizek, Byron R. Voytenko, Denis Holland, David M. Depth-dependent artifacts resulting from ApRES signal clipping |
author_facet |
Vaňková, Irena Nicholls, Keith W. Xie, Surui Parizek, Byron R. Voytenko, Denis Holland, David M. |
author_sort |
Vaňková, Irena |
title |
Depth-dependent artifacts resulting from ApRES signal clipping |
title_short |
Depth-dependent artifacts resulting from ApRES signal clipping |
title_full |
Depth-dependent artifacts resulting from ApRES signal clipping |
title_fullStr |
Depth-dependent artifacts resulting from ApRES signal clipping |
title_full_unstemmed |
Depth-dependent artifacts resulting from ApRES signal clipping |
title_sort |
depth-dependent artifacts resulting from apres signal clipping |
publisher |
Cambridge University Press |
publishDate |
2020 |
url |
http://nora.nerc.ac.uk/id/eprint/528026/ https://nora.nerc.ac.uk/id/eprint/528026/1/depthdependent_artifacts_resulting_from_apres_signal_clipping.pdf https://www.cambridge.org/core/journals/annals-of-glaciology/article/depthdependent-artifacts-resulting-from-apres-signal-clipping/74C8B78B415646A16B15CF418749D9E0 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Annals of Glaciology Greenland |
genre_facet |
Annals of Glaciology Greenland |
op_relation |
https://nora.nerc.ac.uk/id/eprint/528026/1/depthdependent_artifacts_resulting_from_apres_signal_clipping.pdf Vaňková, Irena orcid:0000-0003-4351-3781 Nicholls, Keith W. orcid:0000-0002-2188-4509 Xie, Surui; Parizek, Byron R.; Voytenko, Denis; Holland, David M. 2020 Depth-dependent artifacts resulting from ApRES signal clipping. Annals of Glaciology, 61 (81). 108-113. https://doi.org/10.1017/aog.2020.56 <https://doi.org/10.1017/aog.2020.56> |
op_rights |
cc_by_4 |
op_doi |
https://doi.org/10.1017/aog.2020.56 |
container_title |
Annals of Glaciology |
container_volume |
61 |
container_issue |
81 |
container_start_page |
108 |
op_container_end_page |
113 |
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1790598081967816704 |