Patent · US Expired

Method and apparatus for measuring optical distances

US6148123A · kind A · utility

17Cited by
3References
18Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 17, 1999
Grant dateNov 14, 2000
Priority date
Expiry dateMar 17, 2019

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04B10/07955
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

The optical distance along a buried optical fiber (12) from a particular location (13) therealong to a central facility (10) is measured by first applying an intentional stress to the fiber in the form of a vibration signal (35) transmitted into the ground. A timing signal (36) is transmitted to the central facility (10) in synchronism with the application of the stress. Using the timing signal as a reference, the central facility can determine the time difference between when the stress was applied, and when the central facility detected the stress. From the time difference, and a knowledge of the propagation rate of the timing signal, the central facility can establish the optical distance to the particular location at which the stress was applied.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.