A Periscopic Method for Determining the Three-Dimensional Positions of Fish in Schools

Abstract

The Cartesian coordinates of fish schooling in aquarium tanks are estimated by combining a periscope image via mirrors with a direct view on one photograph. Systematic errors from simple geometrical estimates based on parallax are accurately compensated by calibration using multiple polynomial regression. Once calibration has been carried out, the periscope method has advantages over others in using standard photographic equipment, in reducing measuring time, and in the identification of fish.