| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To enable accurate and proper determination of the speed of a mobile body, reducing random noise. <P>SOLUTION: In this method, a scattered wave from a mobile body is converted into a number sequence d1 by sampling at given intervals; fast Fourier transform of the number sequence d1 is performed for a given number of samples to obtain a frequency spectrum (s1); then, a plurality of frequencies including a maximum peak and a candidate are selected from the frequency spectrum (s2); the number sequence d1 is divided by a cycle corresponding to each of the selected frequencies (s3); synchronous averaging is performed to obtain a mean value after performing an addition for each of the divided portions; fast Fourier transform of a second number sequence d2 obtained by the synchronous averaging is performed for a given number of samples to obtain a second frequency spectrum (s5); a maximum peak is selected from the second frequency spectrum; and a frequency of the maximum peak is determined as a true value of the speed. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
