- 著者
-
小浜 俊一
江川 護
- 出版者
- The Marine Acoustics Society of Japan
- 雑誌
- 海洋音響学会誌 (ISSN:09165835)
- 巻号頁・発行日
- vol.20, no.4, pp.228-233, 1993
In the case of the passive sonar, the LOFAR-Grams of received signals using frequency analysis and variable density visualization technique is widely used for target signal detection. The auto-spectrum analysis method is a signal processing means for the LOFAR-Grams.<BR>As the means to improve the ratio of signal to noise levels (S/N), there is a process of averaging (cumulative processing) analyzed signals used in the LOFAR-Grams.<BR>The discrimination signals smoothed cumulatively in the auto-spectrum method are apt to be difficult due to the nature of noise components, and this auto-spectrum method is not used in this case.<BR>We proposed a new method here, and analyzed experimentally several types of signals of the passive sonar utilizing this method for the LOFAR-Grams.<BR>The results showed that the process gain by cumulative method was obtained in accordance with calculation, and the delay type cross-spectrum method gave processing gain 3 dB higher than the auto-spectrum method.<BR>It was considered that this technique was to be applied extensively to the passive sonar in the future.