The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 15, 1991
Filed:
Sep. 14, 1990
Thomson-CSF, Puteaux, FR;
Abstract
In a method of formation of channels for a sonar, after having sampled at a frequency T=1/4f.sub.0 (where f.sub.0 is the receiving center frequency of the sonar) the signals from the hydrophones of the sonar and having translated them to baseband, the signals thus translated are subsampled with a period T.sub.SE =kT (wherein k is an integer) substantially equal to 1.25 B, where B is the reception bandwidth of the sonar. A first set of signals is subsampled at identical times to form a frontal sector. Two further sets of signals are subsampled with delays between the signals from two adjacent hydrophones equal to T, which determines two side sectors adjacent to the frontal sector. The subsampled signals are then transmitted serially by the towing cable of the sonar device towed array and are processed in FFT circuits which allow to form in each sector a set of channels covering the sector. This allows to considerably reduce the data transmission rate between the towed portion of the sonar and the portion located in the towing ship.