title: Geometric and Optic Characterization of a Hemispherical Dome Port for Underwater Photogrammetry.
abstract: The popularity of automatic photogrammetric techniques has promoted many experiments in underwater scenarios leading to quite impressive visual results, even by non-experts. Despite these achievements, a deep understanding of camera and lens behaviors as well as optical phenomena involved in underwater operations is fundamental to better plan field campaigns and anticipate the achievable results. The paper presents a geometric investigation of a consumer grade underwater camera housing, manufactured by NiMAR and equipped with a 7'' dome port. After a review of flat and dome ports, the work analyzes, using simulations and real experiments, the main optical phenomena involved when operating a camera underwater. Specific aspects which deal with photogrammetric acquisitions are considered with some tests in laboratory and in a swimming pool. Results and considerations are shown and commented.
authors.affiliation: 3D Optical Metrology unit, Bruno Kessler Foundation (FBK), via Sommarive 18, Trento 38123, Italy. fmenna@fbk.eu.
authors.forename: Fabio
authors.initials: F
authors.lastname: Menna
authors.affiliation: 3D Optical Metrology unit, Bruno Kessler Foundation (FBK), via Sommarive 18, Trento 38123, Italy. nocerino@fbk.eu.
authors.forename: Erica
authors.initials: E
authors.lastname: Nocerino
authors.affiliation: Politecnico di Milano, ABC Dep. 3DSurvey Group, via Ponzio 31, Milano 20133, Italy. francesco.fassi@polimi.it.
authors.forename: Francesco
authors.initials: F
authors.lastname: Fassi
authors.affiliation: 3D Optical Metrology unit, Bruno Kessler Foundation (FBK), via Sommarive 18, Trento 38123, Italy. remondino@fbk.eu.
authors.forename: Fabio
authors.initials: F
authors.lastname: Remondino
keywords: camera calibration; depth of field; photogrammetry; underwater