SONAR FOR OBTAINING A TOPOGRAPHIC REPRESENTATION OF AN IMMERSED SURFACE AND UNDERLYING LAYERS

摘要

ABSTRACT OF THE DISCLOSURE: A sonar type device disposed in a movable vehicle to a submerged surface. The device includes an acoustic assembly for determining the speed of movement of the vehicle along a first direction of movement, and at least one transducer whose directivity pattern comprises a main transmission lobe whose axis is inclined relative to the vertical in a plane orthogonal to the first direction and a substantially in the vertical oriented secondary emission lobe. The transducer is capable of emitting and receiving acoustic waves at two different frequencies. In addition, transmitters control the transmission p ?? the transducer of acoustic pulses at two frequencies differen-tes, and receivers realize from the echoes of the pulses transmitted by the transducer echogram of the submerged surface laterally relative to the first direction of movement of the vehicle, for determining the height of water under the vehicle by measuring the propagation time of the waves in the directions of the secon-dary emission lobe and to calculate its speed of movement in a direction orthogonal to the first direction by measuring the frequency of the acoustic waves received a particular direction of the main emission lobe of the transducer.