| 摘要 |
PROBLEM TO BE SOLVED: To provide a Doppler measuring instrument having superior noise-resistant performance, capable of measuring a Doppler shift amount with high accuracy.SOLUTION: Each gravity center calculation section Wt [1:n] is a section including a peak of a power spectrum Pt [fi], and a gravity center frequency fwt [1:n] is calculated in each section Wt [1:n]. A tentative Doppler shift amount is a frequency shift amount when an output in mutual correlation processing of the power spectra Pt [fi], Pr [fi] gets maximum. A gravity center calculation section Wr [1:n] correlated with the gravity center calculation section Wt [1:n] is determined based on the tentative Doppler shift amount, and a gravity center frequency fwr [1:n] of the power spectrum Pr [fi] is calculated in each section Wr [1:n]. Compensation of frequency dependency of a Doppler shift or the like is executed for a difference between the gravity center frequencies fwr [1:n], fwt [1:n] to determine the Doppler shift amount fd. A frequency range of the gravity center calculation section Wr [1:n] is corrected by the Doppler shift amount fd, and the Doppler shift amount fd is determined repeatedly until converged. |
