公开(公告)号：US20210226698A1

公开(公告)日：2021-07-22

申请号：US17301516

申请日：2021-04-05

Applicant: AT&T Intellectual Property II, L.P.

Inventor： ANDREW LEWIS ,  Stuart Russell

IPC: H04B10/071 ,  G01M11/00 ,  G01D5/353 ,  G01H9/00

Abstract: An improved technique for acoustic sensing involves, in one embodiment, launching into a medium, a plurality of groups of pulse-modulated electromagnetic-waves. The frequency of electromagnetic waves in a pulse within a group differs from the frequency of the electromagnetic waves in another pulse within the group. The energy scattered by the medium is detected and, in one embodiment, the beat signal may be used to determine a characteristic of the environment of the medium. For example, if the medium is a buried optical fiber into which light pulses have been launched in accordance with the invention, the presence of acoustic waves within the region of the buried fiber can be detected.