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:
Aug. 18, 1987
Filed:
Sep. 18, 1985
Thomas J Poorman, Houston, TX (US);
David Grissom, Houston, TX (US);
Edward F Carome, Berkley, CA (US);
Western Geophysical Company of America, Houston, TX (US);
Abstract
An optical sound source signature transducer system for use in marine seismic exploration in which coherent radiation from a laser is coupled to unequal length optical paths exposed to modulation by the acoustic energy wave generated by the sound source. The reflected beams from the paths are crosscoupled to generate interference fringes in two output beams out of phase with each other. The fringes in one output beam are counted in an up/down counter to determine the magnitude of the pressure as a function of time. The direction of the pressure change is determined by examination of the phase relationship between the fringes in the output beams. Peaks and valleys in the pressure are detected as phase reversals between the fringes in the output beams be detecting the beginning and end of a fringe in one beam without detecting the beginning or end of a fringe in the other beam therebetween. The direction of counting of the counter is reversed upon detection of a peak or valley in the modulating pressure to maintain the count as an accurate representation of the magnitude of the pressure.