Title:
OPTICAL FIBER STRAIN MEASURING METHOD AND APPARATUS
Document Type and Number:
Japanese Patent JP3502329
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To determine the peak power frequency with good accuracy for the power spectrum of Brillouin scattered light measured by incident pulse light optimum for strain measurement.
SOLUTION: A converting step is a step of performing triangular wave amplitude modulation in which an electric field envelope rises rectilinearly and falls in a time region to convert continuous signal light to pulse light. An operation step has a first step of sorting the measured value of power of Brillouin scattered light taking optical frequency as a variable, a second step of describing a measurement error contained in the measured power in the form of containing/ the peak frequency of power spectrum to be determined, the peak value and full width at half maximum in the variable, and determining the peak frequency under the condition that the sum of squares of the measurement errors of all measured frequencies is minimum,, and a third step of repeatedly determining the peak frequency concerning all measurement points in the direction of length to be obtained.
More Like This:
Inventors:
Hiroshi Naruse
Mitsuhiro Tatsuta
Mitsuhiro Tatsuta
Application Number:
JP2000123290A
Publication Date:
March 02, 2004
Filing Date:
April 24, 2000
Export Citation:
Assignee:
Nippon Telegraph and Telephone Corporation
International Classes:
G01B11/16; G01L1/24; G01M11/00; (IPC1-7): G01B11/16; G01L1/24; G01M11/00
Domestic Patent References:
| JP1090121A | ||||
| JP200133218A | ||||
| JP650842A | ||||
| JP1232228A |
Attorney, Agent or Firm:
Yoshikazu Tani (1 person outside)