Sonar for avoiding sub-surface underwater objects
First Claim
1. A sonar system for avoiding sub-surface underwater objects, for a surface vessel comprising:
- a transmission device for generating pulse transmission signals to discriminate among underwater objects located at different distances from said transmission device;
an acoustic antenna having a plurality of transducers for the receipt of signals wherein said plurality of transducers are formed into a vertically arranged column of n acoustic transducers C1 and Cn for insonifying the returns of signals into sectors such that an elevation sector which corresponds to a collision-risk zone is formed in the vicinity of the surface of the sea in the projected path of the vessel, and further that on reception of signals said transducers form finer channels in the insonified elevation sectors than that of the entire sector received in order to detect locations of submersed objects by way of setting the width of said fine channels to be narrower; and
wherein the placement of the transducers allows reduction of surface reverberation by way of a discrimination between an actual return signal and a surface wave reverberation.
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Accused Products
Abstract
Disclosed is a sonar for avoiding sub-surface underwater objects, for a surface vessel, having its directivity in elevation optimized to observe the surface and its surface reverberation reduced to the minimum. It consists in using an acoustic antenna having two columns of n transducers, the first column insonifying, at transmission, an elevation sector corresponding to the collision-risk zone and forming channels at reception, in the insonified elevation sector, the width of the channels being all the finer as the desired precision of the measurement of the position in elevation is high. The second column is necessary for the localization in relative bearing. The disclosure can be applied to the precise localization in elevation of objects located in the path of a vessel.
43 Citations
10 Claims
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1. A sonar system for avoiding sub-surface underwater objects, for a surface vessel comprising:
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a transmission device for generating pulse transmission signals to discriminate among underwater objects located at different distances from said transmission device; an acoustic antenna having a plurality of transducers for the receipt of signals wherein said plurality of transducers are formed into a vertically arranged column of n acoustic transducers C1 and Cn for insonifying the returns of signals into sectors such that an elevation sector which corresponds to a collision-risk zone is formed in the vicinity of the surface of the sea in the projected path of the vessel, and further that on reception of signals said transducers form finer channels in the insonified elevation sectors than that of the entire sector received in order to detect locations of submersed objects by way of setting the width of said fine channels to be narrower; and wherein the placement of the transducers allows reduction of surface reverberation by way of a discrimination between an actual return signal and a surface wave reverberation. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification