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.

Date of Patent:
Jun. 17, 1997

Filed:

Sep. 15, 1995
Applicant:
Inventor:

Yukio Sai, Tokorozawa, JP;

Assignee:

Kabushiki Kaisha Toshiba, Kawasaki, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01K / ; G01K / ;
U.S. Cl.
CPC ...
374161 ; 374137 ; 374120 ; 25022718 ; 25022723 ; 356 44 ; 356301 ;
Abstract

In a temperature distribution measuring apparatus which projects pulsed-light into an optical fiber, measures Raman spectrum of backscattered light occurred in the optical fiber, and obtains a temperature distribution along the optical fiber, to improve the positional resolution, it is necessary to narrow the width of the incident pulsed-light. A response of the backscattered light to a pulsed-light of a finite width is considered to be convolution and deconvolution of the measured value of the backscattered light is performed to obtain an impulse response. Deconvolution which is an inverse transform requires a waveform of the incident light and which is previously measured. When deconvolution is performed by using an inverse matrix of the incident light, it is necessary to calculate the inverse matrix by means of an iteration method. An optimum number of iterations of the iteration method is determined such that an error of a measured value for a known temperature used as an evaluation function is minimum or a result of deconvolution on Fresnel reflected light shows a linear waveform.


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