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:
Sep. 11, 2007
Filed:
Feb. 07, 2005
Robert Michael Payton, Portsmouth, RI (US);
Robert Michael Payton, Portsmouth, RI (US);
The United States of America as represented by the Secretary of the Navy, Washington, DC (US);
Abstract
A CW lightwave modulated by a continuously reiterated autocorrelated spectrum-spreading signal is launched into an end of a span of ordinary optical fiber cable. Portions of this lightwave back propagate to the launch end from a continuum of span locations because of innate fiber properties including Rayleigh effects. This is picked off the launch end and heterodyned producing an r.f. beat signal. The beat signal is processed by a plurality (can be thousands) of multifunction despreader, autocorrelator and de-multiplexer units respectively operated in different time delayed relationships to the timing base of launch signal reiteration. This provides r.f. time-domain reflectometry outputs representative of acoustic, or other signals incident upon virtual sensors at positions along the fiber corresponding to the various delay relationships. Material attenuation of undesired noises (e.g., reflections due to presence of couplers in the fiber cable line) is effected by the spectrum spreading and de-spreading.