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An Application of Close Range Photogrammetry In Dolphin Studies
Author(s) -
Bräger S.,
Chong A. K.
Publication year - 1999
Publication title -
the photogrammetric record
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.638
H-Index - 51
eISSN - 1477-9730
pISSN - 0031-868X
DOI - 10.1111/0031-868x.00139
Subject(s) - photogrammetry , endangered species , range (aeronautics) , population , measure (data warehouse) , threatened species , fishery , geography , calibration , environmental science , remote sensing , computer science , ecology , statistics , biology , mathematics , engineering , habitat , demography , database , aerospace engineering , sociology
Dolphins are agile animals and are very difficult to measure at sea. However, for the conservation of threatened or endangered species, measurement may be vital because it allows a demographic analysis of the population. Hector's dolphin (Cephalorhynchus hectori) is a rare species living only in coastal waters around New Zealand where it is studied from small boats. This paper describes a stereophotogrammetric technique developed to measure body length accurately at sea without having to capture the individual. Constant calibration with the use of a control frame allowed accurate body length measurements of dolphins to be made with this low cost system, with a measurement error of 4 per cent to 6 per cent of actual length.