Thomson-csf

Claude Gragnolati

Charles Maerfeld

Michel Lagier

Michel Josserand

Jena-Pierre Besombes

Jean-Georges Malcor

Didier Thollon

A low-frequency hydrophone for a sonar array comprises at least a lacunary ceramics element with open porosity saturated by a viscous fluid, on which metal electrodes have been deposited. This hydrophone forms a high-pass filter whose cutoff frequency is adjusted by modulating the area of the electrodes. The present invention may find particular application in towed linear arrays and passive sonars.

Low-frequency hydrophone and sonar array including such hydrophones

A geophone designed to measure the vibrations of bodies, especially vibrations in the earth's crust, comprises two-strip sensors made of piezoelectric polymer, embedded by one end in the geophone casing and resting freely, by one side, on the inertial mass of the geophone, thus enabling the making of geophones with a very wide pass-band.

Geophone with a sensitive element made of piezoelectric polymer

A directional velocity hydrophone is provided which does not appreciably disturb the particular movement of the fluid in which it is plunged and which comprises bending blades disposed in a ring and embedded in an inertial mass, which deliver an electric current substantially proportional to the particular speed of the fluid.

Growing community of inventors

Cannes, France

Claude Gragnolati