Distance estimation experiment for aerial minke whale surveys
A comparative study between aerial cue–counting and digital photography surveys for minke whales conducted in Faxaflói Bay in September 2003 is used to check the perpendicular distances estimated by the cue-counting observers. The study involved 2 aircraft with the photo plane at 1,700 feet flying ab...
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2009
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ftdoajarticles:oai:doaj.org/article:8520526e956e42499e065da99a87172e 2023-05-15T15:36:38+02:00 Distance estimation experiment for aerial minke whale surveys Lars Witting Daniel G Pike 2009-09-01T00:00:00Z https://doi.org/10.7557/3.2709 https://doaj.org/article/8520526e956e42499e065da99a87172e EN eng Septentrio Academic Publishing https://septentrio.uit.no/index.php/NAMMCOSP/article/view/2709 https://doaj.org/toc/1560-2206 https://doaj.org/toc/2309-2491 1560-2206 2309-2491 doi:10.7557/3.2709 https://doaj.org/article/8520526e956e42499e065da99a87172e NAMMCO Scientific Publications, Vol 7, Iss 0, Pp 111-116 (2009) minke whales Balaenoptera physalus surveys distance estimation Ecology QH540-549.5 article 2009 ftdoajarticles https://doi.org/10.7557/3.2709 2022-12-31T06:35:39Z A comparative study between aerial cue–counting and digital photography surveys for minke whales conducted in Faxaflói Bay in September 2003 is used to check the perpendicular distances estimated by the cue-counting observers. The study involved 2 aircraft with the photo plane at 1,700 feet flying above the cue–counting plane at 750 feet. The observer–based distance estimates were calculated from head angles estimated by angle-boards and declination angles estimated by declinometers. These distances were checked against image–based estimates of the perpendicular distance to the same whale. The 2 independent distance estimates were obtained for 21 sightings of minke whale, and there was a good agreement between the 2 types of estimates. The relative absolute deviations between the 2 estimates were on average 23% (se: 6%), with the errors in the observer–based distance estimates resembling that of a log-normal distribution. The linear regression of the observer–based estimates (obs) on the image–based estimates (img) was Obs=1.1Img (R2=0.85) with an intercept fixed at zero. There was no evidence of a distance estimation bias that could generate a positive bias in the absolute abundance estimated by cue–counting. Article in Journal/Newspaper Balaenoptera physalus minke whale Directory of Open Access Journals: DOAJ Articles NAMMCO Scientific Publications 7 111 |
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Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
minke whales Balaenoptera physalus surveys distance estimation Ecology QH540-549.5 |
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minke whales Balaenoptera physalus surveys distance estimation Ecology QH540-549.5 Lars Witting Daniel G Pike Distance estimation experiment for aerial minke whale surveys |
topic_facet |
minke whales Balaenoptera physalus surveys distance estimation Ecology QH540-549.5 |
description |
A comparative study between aerial cue–counting and digital photography surveys for minke whales conducted in Faxaflói Bay in September 2003 is used to check the perpendicular distances estimated by the cue-counting observers. The study involved 2 aircraft with the photo plane at 1,700 feet flying above the cue–counting plane at 750 feet. The observer–based distance estimates were calculated from head angles estimated by angle-boards and declination angles estimated by declinometers. These distances were checked against image–based estimates of the perpendicular distance to the same whale. The 2 independent distance estimates were obtained for 21 sightings of minke whale, and there was a good agreement between the 2 types of estimates. The relative absolute deviations between the 2 estimates were on average 23% (se: 6%), with the errors in the observer–based distance estimates resembling that of a log-normal distribution. The linear regression of the observer–based estimates (obs) on the image–based estimates (img) was Obs=1.1Img (R2=0.85) with an intercept fixed at zero. There was no evidence of a distance estimation bias that could generate a positive bias in the absolute abundance estimated by cue–counting. |
format |
Article in Journal/Newspaper |
author |
Lars Witting Daniel G Pike |
author_facet |
Lars Witting Daniel G Pike |
author_sort |
Lars Witting |
title |
Distance estimation experiment for aerial minke whale surveys |
title_short |
Distance estimation experiment for aerial minke whale surveys |
title_full |
Distance estimation experiment for aerial minke whale surveys |
title_fullStr |
Distance estimation experiment for aerial minke whale surveys |
title_full_unstemmed |
Distance estimation experiment for aerial minke whale surveys |
title_sort |
distance estimation experiment for aerial minke whale surveys |
publisher |
Septentrio Academic Publishing |
publishDate |
2009 |
url |
https://doi.org/10.7557/3.2709 https://doaj.org/article/8520526e956e42499e065da99a87172e |
genre |
Balaenoptera physalus minke whale |
genre_facet |
Balaenoptera physalus minke whale |
op_source |
NAMMCO Scientific Publications, Vol 7, Iss 0, Pp 111-116 (2009) |
op_relation |
https://septentrio.uit.no/index.php/NAMMCOSP/article/view/2709 https://doaj.org/toc/1560-2206 https://doaj.org/toc/2309-2491 1560-2206 2309-2491 doi:10.7557/3.2709 https://doaj.org/article/8520526e956e42499e065da99a87172e |
op_doi |
https://doi.org/10.7557/3.2709 |
container_title |
NAMMCO Scientific Publications |
container_volume |
7 |
container_start_page |
111 |
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1766366998965518336 |