A simple new algorithm to filter marine mammal Argos locations
During recent decades satellite telemetry using the Argos system has been used extensively to track many species of marine mammals. However, the aquatic behavior of most of these species results in a high number of locations with low or unknown accuracy. Argos data are often filtered to reduce the n...
Published in: | Marine Mammal Science |
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2008
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Online Access: | https://research-portal.st-andrews.ac.uk/en/publications/4c509e2b-3f90-49f0-a2b9-b29a3cbcd817 https://doi.org/10.1111/j.1748-7692.2007.00180.x http://www.scopus.com/inward/record.url?scp=42449153696&partnerID=8YFLogxK |
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ftunstandrewcris:oai:research-portal.st-andrews.ac.uk:publications/4c509e2b-3f90-49f0-a2b9-b29a3cbcd817 2024-10-20T14:04:29+00:00 A simple new algorithm to filter marine mammal Argos locations Freitas, Carla Lydersen, Christian Fedak, Michael A. Kovacs, Kit M. 2008-04 https://research-portal.st-andrews.ac.uk/en/publications/4c509e2b-3f90-49f0-a2b9-b29a3cbcd817 https://doi.org/10.1111/j.1748-7692.2007.00180.x http://www.scopus.com/inward/record.url?scp=42449153696&partnerID=8YFLogxK eng eng info:eu-repo/semantics/restrictedAccess Freitas , C , Lydersen , C , Fedak , M A & Kovacs , K M 2008 , ' A simple new algorithm to filter marine mammal Argos locations ' , Marine Mammal Science , vol. 24 , no. 2 , pp. 315-325 . https://doi.org/10.1111/j.1748-7692.2007.00180.x cetaceans location class accuracy location errors path filter pinnipeds satellite telemetry SEALS HALICHOERUS-GRYPUS SOUTHERN ELEPHANT SEALS SATELLITE-TRACKING GRAY SEALS TELEMETRY ACCURACY BEHAVIOR article 2008 ftunstandrewcris https://doi.org/10.1111/j.1748-7692.2007.00180.x 2024-10-09T23:40:50Z During recent decades satellite telemetry using the Argos system has been used extensively to track many species of marine mammals. However, the aquatic behavior of most of these species results in a high number of locations with low or unknown accuracy. Argos data are often filtered to reduce the noise produced by these locations, typically by removing data points requiring unrealistic swimming speeds. Unfortunately, this method excludes a considerable number of good-quality locations that have high traveling speeds that are the result of two locations being taken very close in time. We present an alternative algorithm, based on swimming speed, distance between successive locations, and turning angles. This new filter was tested on 67 tracks from nine different marine mammal species: ringed, bearded, gray, harbor, southern elephant, and Antarctic fur seals, walruses, belugas, and nar-whals. The algorithm removed similar percentages of low-quality locations (Argos location classes [LC] B and A) compared to a filter based solely on swimming speed, but preserved significantly higher percentages of good-quality positions (mean SE% of locations removed was 4.1 +/- 0.8% vs. 12.6 +/- 1.2% for LC 3; 6.8 +/- 0.6% vs. 15.7 +/- 0.9% for LC 2; and 11.4 +/- 0.7% vs. 21.0 +/- 0.97o for LC 1). The new filter was also more effective at removing unlikely, conspicuous deviations from the track's path, resulting in fewer locations being registered on land and a significant reduction in home range size, when using the Minimum Convex Polygon method, which is sensitive to outliers. Article in Journal/Newspaper Antarc* Antarctic Antarctic Fur Seals Beluga* Elephant Seals Southern Elephant Seals walrus* University of St Andrews: Research Portal Antarctic Marine Mammal Science 24 2 315 325 |
institution |
Open Polar |
collection |
University of St Andrews: Research Portal |
op_collection_id |
ftunstandrewcris |
language |
English |
topic |
cetaceans location class accuracy location errors path filter pinnipeds satellite telemetry SEALS HALICHOERUS-GRYPUS SOUTHERN ELEPHANT SEALS SATELLITE-TRACKING GRAY SEALS TELEMETRY ACCURACY BEHAVIOR |
spellingShingle |
cetaceans location class accuracy location errors path filter pinnipeds satellite telemetry SEALS HALICHOERUS-GRYPUS SOUTHERN ELEPHANT SEALS SATELLITE-TRACKING GRAY SEALS TELEMETRY ACCURACY BEHAVIOR Freitas, Carla Lydersen, Christian Fedak, Michael A. Kovacs, Kit M. A simple new algorithm to filter marine mammal Argos locations |
topic_facet |
cetaceans location class accuracy location errors path filter pinnipeds satellite telemetry SEALS HALICHOERUS-GRYPUS SOUTHERN ELEPHANT SEALS SATELLITE-TRACKING GRAY SEALS TELEMETRY ACCURACY BEHAVIOR |
description |
During recent decades satellite telemetry using the Argos system has been used extensively to track many species of marine mammals. However, the aquatic behavior of most of these species results in a high number of locations with low or unknown accuracy. Argos data are often filtered to reduce the noise produced by these locations, typically by removing data points requiring unrealistic swimming speeds. Unfortunately, this method excludes a considerable number of good-quality locations that have high traveling speeds that are the result of two locations being taken very close in time. We present an alternative algorithm, based on swimming speed, distance between successive locations, and turning angles. This new filter was tested on 67 tracks from nine different marine mammal species: ringed, bearded, gray, harbor, southern elephant, and Antarctic fur seals, walruses, belugas, and nar-whals. The algorithm removed similar percentages of low-quality locations (Argos location classes [LC] B and A) compared to a filter based solely on swimming speed, but preserved significantly higher percentages of good-quality positions (mean SE% of locations removed was 4.1 +/- 0.8% vs. 12.6 +/- 1.2% for LC 3; 6.8 +/- 0.6% vs. 15.7 +/- 0.9% for LC 2; and 11.4 +/- 0.7% vs. 21.0 +/- 0.97o for LC 1). The new filter was also more effective at removing unlikely, conspicuous deviations from the track's path, resulting in fewer locations being registered on land and a significant reduction in home range size, when using the Minimum Convex Polygon method, which is sensitive to outliers. |
format |
Article in Journal/Newspaper |
author |
Freitas, Carla Lydersen, Christian Fedak, Michael A. Kovacs, Kit M. |
author_facet |
Freitas, Carla Lydersen, Christian Fedak, Michael A. Kovacs, Kit M. |
author_sort |
Freitas, Carla |
title |
A simple new algorithm to filter marine mammal Argos locations |
title_short |
A simple new algorithm to filter marine mammal Argos locations |
title_full |
A simple new algorithm to filter marine mammal Argos locations |
title_fullStr |
A simple new algorithm to filter marine mammal Argos locations |
title_full_unstemmed |
A simple new algorithm to filter marine mammal Argos locations |
title_sort |
simple new algorithm to filter marine mammal argos locations |
publishDate |
2008 |
url |
https://research-portal.st-andrews.ac.uk/en/publications/4c509e2b-3f90-49f0-a2b9-b29a3cbcd817 https://doi.org/10.1111/j.1748-7692.2007.00180.x http://www.scopus.com/inward/record.url?scp=42449153696&partnerID=8YFLogxK |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic Antarctic Fur Seals Beluga* Elephant Seals Southern Elephant Seals walrus* |
genre_facet |
Antarc* Antarctic Antarctic Fur Seals Beluga* Elephant Seals Southern Elephant Seals walrus* |
op_source |
Freitas , C , Lydersen , C , Fedak , M A & Kovacs , K M 2008 , ' A simple new algorithm to filter marine mammal Argos locations ' , Marine Mammal Science , vol. 24 , no. 2 , pp. 315-325 . https://doi.org/10.1111/j.1748-7692.2007.00180.x |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1111/j.1748-7692.2007.00180.x |
container_title |
Marine Mammal Science |
container_volume |
24 |
container_issue |
2 |
container_start_page |
315 |
op_container_end_page |
325 |
_version_ |
1813453333026832384 |