Abstract: A temperature compensation system that adjusts the temperature of an acoustic lens fluid in a prescribed manner to maintain the index of refraction of the fluid constant relative to the surrounding water thereby maintaining the focal length of the lens constant over its operating temperature range. The system comprises two temperature sensors, a programmed lens fluid temperature prescriber and an error amplifier all cooperating to direct a servomechanism system to adjust a temperature control system to either heat or cool the lens fluid to the prescribed temperature so that its index or refraction and focal length are held constant.

Abstract: An omnidirectional hydrophone using particles suspended in a liquid acoustically coupled to a conducting environment for detecting acoustic waves by providing scattering of internally generated electromagnetic radiation from particles driven by the acoustic waves.