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:
Jul. 07, 2026
Filed:
Aug. 16, 2021
Ntt, Inc., Tokyo, JP;
Tatsuya Okamoto, Musashino, JP;
Daisuke Iida, Musashino, JP;
Yusuke Koshikiya, Musashino, JP;
Nazuki Honda, Musashino, JP;
NTT, Inc., Tokyo, JP;
Abstract
The present disclosure provides an underground facility position contrast system S, which includes: a scattered light intensity distribution measurement devicefor measuring, when an earthquake vibration is applied to an optical fiber F laid underground, a change over time in a scattered light intensity distribution in a longitudinal direction of the optical fiber F; and an underground facility position contrast devicefor measuring a change over time in a distortion response distribution in the longitudinal direction of the optical fiber F based on the change over time in the scattered light intensity distribution in the longitudinal direction of the optical fiber F, estimating an underground facility state of the optical fiber F based on the change over time in the distortion response distribution in the longitudinal direction of the optical fiber F, and associating the underground facility position of the optical fiber F with a longitudinal distance of the optical fiber F.