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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Cambridge University Press
2020
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Online Access: | https://doi.org/10.1017/aog.2020.56 https://doaj.org/article/ad45e1a04dca4ea08e8b9dc7011b7899 |
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ftdoajarticles:oai:doaj.org/article:ad45e1a04dca4ea08e8b9dc7011b7899 2023-05-15T13:29:36+02:00 Depth-dependent artifacts resulting from ApRES signal clipping Irena Vaňková Keith W. Nicholls Surui Xie Byron R. Parizek Denis Voytenko David M. Holland 2020-04-01T00:00:00Z https://doi.org/10.1017/aog.2020.56 https://doaj.org/article/ad45e1a04dca4ea08e8b9dc7011b7899 EN eng Cambridge University Press https://www.cambridge.org/core/product/identifier/S0260305520000567/type/journal_article https://doaj.org/toc/0260-3055 https://doaj.org/toc/1727-5644 doi:10.1017/aog.2020.56 0260-3055 1727-5644 https://doaj.org/article/ad45e1a04dca4ea08e8b9dc7011b7899 Annals of Glaciology, Vol 61, Pp 108-113 (2020) Glaciological instruments and methods ground-penetrating radar ice thickness measurements Meteorology. Climatology QC851-999 article 2020 ftdoajarticles https://doi.org/10.1017/aog.2020.56 2023-03-12T01:31:55Z 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 Directory of Open Access Journals: DOAJ Articles Greenland Annals of Glaciology 61 81 108 113 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Glaciological instruments and methods ground-penetrating radar ice thickness measurements Meteorology. Climatology QC851-999 |
spellingShingle |
Glaciological instruments and methods ground-penetrating radar ice thickness measurements Meteorology. Climatology QC851-999 Irena Vaňková Keith W. Nicholls Surui Xie Byron R. Parizek Denis Voytenko David M. Holland Depth-dependent artifacts resulting from ApRES signal clipping |
topic_facet |
Glaciological instruments and methods ground-penetrating radar ice thickness measurements Meteorology. Climatology QC851-999 |
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 |
Irena Vaňková Keith W. Nicholls Surui Xie Byron R. Parizek Denis Voytenko David M. Holland |
author_facet |
Irena Vaňková Keith W. Nicholls Surui Xie Byron R. Parizek Denis Voytenko David M. Holland |
author_sort |
Irena Vaňková |
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 |
https://doi.org/10.1017/aog.2020.56 https://doaj.org/article/ad45e1a04dca4ea08e8b9dc7011b7899 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Annals of Glaciology Greenland |
genre_facet |
Annals of Glaciology Greenland |
op_source |
Annals of Glaciology, Vol 61, Pp 108-113 (2020) |
op_relation |
https://www.cambridge.org/core/product/identifier/S0260305520000567/type/journal_article https://doaj.org/toc/0260-3055 https://doaj.org/toc/1727-5644 doi:10.1017/aog.2020.56 0260-3055 1727-5644 https://doaj.org/article/ad45e1a04dca4ea08e8b9dc7011b7899 |
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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1766001404331163648 |