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CENSUS OF GREY SEALS BY AERIAL PHOTOGRAPHY
Author(s) -
Hiby A. R.,
Thompson D.,
Ward A. J.
Publication year - 1988
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/j.1477-9730.1988.tb00607.x
Subject(s) - aerial photography , aerial survey , shutter , mount , photography , remote sensing , focal length , high resolution , geography , wildlife , cartography , computer vision , computer science , optics , art , visual arts , lens (geology) , physics , ecology , biology , operating system
The factors determining resolution in aerial photography of wildlife concentrations are considered and two developments that improve resolution with inexpensive equipment are described. Firstly, a rocking camera mount has been constructed that compensates for apparent image motion resulting from forward movement of the aircraft. The mount allows slower shutter speeds to be used so that aerial surveys can be conducted using high resolution colour film under poor light conditions. Secondly, critical prefocusing to the survey flying height is carried out, even for lenses of short focal length. Aerial photography of grey seal breeding colonies is used to illustrate these developments.