| 摘要 |
PROBLEM TO BE SOLVED: To execute a high-sensitivity long-distance measurement economically in monitoring an optical transmission system using a C-OTDR.SOLUTION: A frequency drift amount to be corrected is calculated by comparing the frequency component of a test optical pulse with the peak frequency of the power spectrum of measured back-scattered light, whereby it is made possible to obtain a high-sensitivity distribution of back-scattered light intensities. In an optical signal arithmetic processing process, the present invention has a preliminary step of calculating, after dividing an optical path into discretionary sections, the peak frequency of the power spectrum of back-scattered light for each of the sections, and a calculation step of correcting the extraction frequency of a power spectrum amplitude value by using the obtained per-section peak frequency and then calculating the distribution of back-scattered light intensities on the basis of the power spectrum amplitude value extracted by the corrected frequency. |
