| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a signal processing system for a passive sonar, in which a whitening process in conventional method can be omitted and in which the computing amount can be reduced by using a linear predication analysis in order to suppress the wide dynamic range of submarine noise. SOLUTION: A linear prediction filter 1 is found with respect to an input signal S1 in the first half of a block diagram. In a part in which a value passed through the filter 1 is subtracted from the input signal S1, a spectrum envelope is removed from the spectrum of the input signal S1. The fine structure of a spectrum which is obtained by it becomes nearly flat with reference to a frequency in terms of a band, and the wide dynamic range of the submarine noise is suppressed while a local feature is left. A part after an FFT processing part 3 in the latter half is nearly the same as a conventional display processing operation. Since a dynamic range is already suppressed in the first half part, it is not required to subtract a nearly representative value with reference to a power spectrum value which is called a whitening value in the conventional method.</p> |
