Remote sphere-positioning system for calibration of hull-mounted echo-sounder transducers

This system provides rapid and fine remote adjustment of line lengths when calibrating hull-mounted echo-sounder transducers by the standard sphere method. It consists of three motor-driven reels a control panel connected to the reels by 50m of cable, and three attachable outriggers which can be adjusted to the vessels dimensions and the position of any hull-mounted transducer needing calibration. The outriggers can also be easily adapted for the calibration of suspended or towbody-mounted transducers. The system greatly simplifies and accelerates sphere calibration, leading to more frequent, thorough and accurate calibration. Two-dimensional beam-plotting in particular, is greatly facilitated.