SIMULTANEOUS MEASUREMENT OF THE POSITION AND SHAPE OF A SWIMMING FISHBY COMBINING A FRINGE PATTERN PROJECTION METHOD WITH A LASER-SCANNINGTECHNIQUE

A novel scanning fringe projection method is developed to simultaneous ly measure the variations in both position and shape of a swimming fis h. This method combines the commonly used fringe pattern projection me thod and a laser scanning technique into one optical system. In this n ew system, one or more reference fringes are generated by an acousto-o ptic deflector, and laser triangulation is used to determine the order of the reference fringe. These reference fringes are then combined wi th the conventional fringe pattern, and the fringe order is determined from the reference fringes. The method enables us to simultaneously m easure the position and shape of a moving object. We successfully appl y the method to a swimming fish. (C) 1998 Society of Photo-Optical ins trumentation Engineers. [S0091-3286(98)02005-4].