Development of an ultrasonic ranging device for hydrofoil height control

This paper concerns itself with a special ultrasonic ranging device, which was designed and developed by The Boeing Company, to be used on submerged foil type hydrofoils for measurement and control of the height of the.ship´s hull above the water. This device differs from acoustical systems normally used in the marine field in that it operates in air rather than water. Topics discussed include: - Reasons for Selecting Air/Ultrasonic Approach - History of Development - System Description & Theory of Operation - Developmental Problems and Solutions - Operational History