Data from: Quantitative ornithology with a commercial marine radar: standard-target calibration, target detection and tracking, and measurement of echoes from individuals and flocks
Marine surveillance radars are commonly used for radar ornithology, but they are rarely calibrated. This prevents them from measuring the radar cross-sections (RCS) of the birds under study. Furthermore, if the birds are aggregated too closely for the radar to resolve them individually, the bulk vol...
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Data Archiving and Networked Services (DANS)
2017
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Online Access: | https://doi.org/10.5061/dryad.45gb4 |
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fttriple:oai:gotriple.eu:50|dedup_wf_001::60bf3dfb922907f107bb90b8ecc0902c 2023-05-15T18:27:24+02:00 Data from: Quantitative ornithology with a commercial marine radar: standard-target calibration, target detection and tracking, and measurement of echoes from individuals and flocks Urmy, Samuel S. Warren, Joseph D. 2017-01-01 https://doi.org/10.5061/dryad.45gb4 undefined unknown Data Archiving and Networked Services (DANS) http://dx.doi.org/10.5061/dryad.45gb4 https://dx.doi.org/10.5061/dryad.45gb4 lic_creative-commons oai:easy.dans.knaw.nl:easy-dataset:96037 10.5061/dryad.45gb4 oai:services.nod.dans.knaw.nl:Products/dans:oai:easy.dans.knaw.nl:easy-dataset:96037 10|re3data_____::84e123776089ce3c7a33db98d9cd15a8 10|openaire____::9e3be59865b2c1c335d32dae2fe7b254 re3data_____::r3d100000044 10|eurocrisdris::fe4903425d9040f680d8610d9079ea14 10|re3data_____::94816e6421eeb072e7742ce6a9decc5f 10|openaire____::081b82f96300b6a6e3d282bad31cb6e2 Life sciences medicine and health care radar ornithology seabirds Great Gull Island Long Island Sound 41.2018N 72.1192W New York Block Island Sound Sterna hirundo Sterna dougalli Sterna dougallii radar cross-section info envir Dataset https://vocabularies.coar-repositories.org/resource_types/c_ddb1/ 2017 fttriple https://doi.org/10.5061/dryad.45gb4 2023-01-22T16:51:46Z Marine surveillance radars are commonly used for radar ornithology, but they are rarely calibrated. This prevents them from measuring the radar cross-sections (RCS) of the birds under study. Furthermore, if the birds are aggregated too closely for the radar to resolve them individually, the bulk volume reflectivity cannot be translated into a numerical density. We calibrated a commercial off-the-shelf marine radar using a standard spherical target of known RCS. Once calibrated, the radar was used to measure the RCS of common and roseate terns (Sterna hirundo L. and Sterna dougallii Montagu) tracked from a land-based installation at their breeding colony on Great Gull Island, NY, USA. We also integrated echoes from flocks of terns, comparing these total flock cross-sections with visual counts from photos taken at the same time as the radar measurements. The radar's calibration parameters were determined with 1% error. RCS measurements made after calibration were expected to be accurate within ±2 dB. Mean tern RCS was estimated at -28 dB relative to one square meter (dBsm), agreeing in magnitude with a simple theoretical model. RCS was 3-4 dB higher when birds’ aspect angles were broadside to the radar beam compared with head- or tail-on. Integrated flock cross-section was linearly related to the number of birds. The slope of this line, an independent estimate of RCS, was -32 dBsm, within an order of magnitude of the estimate from individual birds, and near the middle of the frequency distribution of RCS values. These results indicate that a calibrated marine radar can count the birds in an aggregation via echo integration. Field calibration of marine radars is practical, enables useful measurements, and should be done more often. Raw radar files from tern colony on Great Gull Island, NYZipped archive containing 200 raw radar sweeps recorded as NetCDF files on 22 July 2014 on Great Gull Island, NY. Each file contains a single sweep of the radar's antenna, with three variables. The variable "amplitude" contains 2-D ... Dataset Sterna hirundo Unknown Long Island Montagu ENVELOPE(-26.333,-26.333,-58.417,-58.417) Long Island Sound ENVELOPE(-79.366,-79.366,54.800,54.800) Gull Island ENVELOPE(-55.315,-55.315,49.533,49.533) Block Island ENVELOPE(-62.347,-62.347,67.051,67.051) |
institution |
Open Polar |
collection |
Unknown |
op_collection_id |
fttriple |
language |
unknown |
topic |
Life sciences medicine and health care radar ornithology seabirds Great Gull Island Long Island Sound 41.2018N 72.1192W New York Block Island Sound Sterna hirundo Sterna dougalli Sterna dougallii radar cross-section info envir |
spellingShingle |
Life sciences medicine and health care radar ornithology seabirds Great Gull Island Long Island Sound 41.2018N 72.1192W New York Block Island Sound Sterna hirundo Sterna dougalli Sterna dougallii radar cross-section info envir Urmy, Samuel S. Warren, Joseph D. Data from: Quantitative ornithology with a commercial marine radar: standard-target calibration, target detection and tracking, and measurement of echoes from individuals and flocks |
topic_facet |
Life sciences medicine and health care radar ornithology seabirds Great Gull Island Long Island Sound 41.2018N 72.1192W New York Block Island Sound Sterna hirundo Sterna dougalli Sterna dougallii radar cross-section info envir |
description |
Marine surveillance radars are commonly used for radar ornithology, but they are rarely calibrated. This prevents them from measuring the radar cross-sections (RCS) of the birds under study. Furthermore, if the birds are aggregated too closely for the radar to resolve them individually, the bulk volume reflectivity cannot be translated into a numerical density. We calibrated a commercial off-the-shelf marine radar using a standard spherical target of known RCS. Once calibrated, the radar was used to measure the RCS of common and roseate terns (Sterna hirundo L. and Sterna dougallii Montagu) tracked from a land-based installation at their breeding colony on Great Gull Island, NY, USA. We also integrated echoes from flocks of terns, comparing these total flock cross-sections with visual counts from photos taken at the same time as the radar measurements. The radar's calibration parameters were determined with 1% error. RCS measurements made after calibration were expected to be accurate within ±2 dB. Mean tern RCS was estimated at -28 dB relative to one square meter (dBsm), agreeing in magnitude with a simple theoretical model. RCS was 3-4 dB higher when birds’ aspect angles were broadside to the radar beam compared with head- or tail-on. Integrated flock cross-section was linearly related to the number of birds. The slope of this line, an independent estimate of RCS, was -32 dBsm, within an order of magnitude of the estimate from individual birds, and near the middle of the frequency distribution of RCS values. These results indicate that a calibrated marine radar can count the birds in an aggregation via echo integration. Field calibration of marine radars is practical, enables useful measurements, and should be done more often. Raw radar files from tern colony on Great Gull Island, NYZipped archive containing 200 raw radar sweeps recorded as NetCDF files on 22 July 2014 on Great Gull Island, NY. Each file contains a single sweep of the radar's antenna, with three variables. The variable "amplitude" contains 2-D ... |
format |
Dataset |
author |
Urmy, Samuel S. Warren, Joseph D. |
author_facet |
Urmy, Samuel S. Warren, Joseph D. |
author_sort |
Urmy, Samuel S. |
title |
Data from: Quantitative ornithology with a commercial marine radar: standard-target calibration, target detection and tracking, and measurement of echoes from individuals and flocks |
title_short |
Data from: Quantitative ornithology with a commercial marine radar: standard-target calibration, target detection and tracking, and measurement of echoes from individuals and flocks |
title_full |
Data from: Quantitative ornithology with a commercial marine radar: standard-target calibration, target detection and tracking, and measurement of echoes from individuals and flocks |
title_fullStr |
Data from: Quantitative ornithology with a commercial marine radar: standard-target calibration, target detection and tracking, and measurement of echoes from individuals and flocks |
title_full_unstemmed |
Data from: Quantitative ornithology with a commercial marine radar: standard-target calibration, target detection and tracking, and measurement of echoes from individuals and flocks |
title_sort |
data from: quantitative ornithology with a commercial marine radar: standard-target calibration, target detection and tracking, and measurement of echoes from individuals and flocks |
publisher |
Data Archiving and Networked Services (DANS) |
publishDate |
2017 |
url |
https://doi.org/10.5061/dryad.45gb4 |
long_lat |
ENVELOPE(-26.333,-26.333,-58.417,-58.417) ENVELOPE(-79.366,-79.366,54.800,54.800) ENVELOPE(-55.315,-55.315,49.533,49.533) ENVELOPE(-62.347,-62.347,67.051,67.051) |
geographic |
Long Island Montagu Long Island Sound Gull Island Block Island |
geographic_facet |
Long Island Montagu Long Island Sound Gull Island Block Island |
genre |
Sterna hirundo |
genre_facet |
Sterna hirundo |
op_source |
oai:easy.dans.knaw.nl:easy-dataset:96037 10.5061/dryad.45gb4 oai:services.nod.dans.knaw.nl:Products/dans:oai:easy.dans.knaw.nl:easy-dataset:96037 10|re3data_____::84e123776089ce3c7a33db98d9cd15a8 10|openaire____::9e3be59865b2c1c335d32dae2fe7b254 re3data_____::r3d100000044 10|eurocrisdris::fe4903425d9040f680d8610d9079ea14 10|re3data_____::94816e6421eeb072e7742ce6a9decc5f 10|openaire____::081b82f96300b6a6e3d282bad31cb6e2 |
op_relation |
http://dx.doi.org/10.5061/dryad.45gb4 https://dx.doi.org/10.5061/dryad.45gb4 |
op_rights |
lic_creative-commons |
op_doi |
https://doi.org/10.5061/dryad.45gb4 |
_version_ |
1766209481806446592 |