An Optimized Algorithm of Feature Extraction for Vessel Base Frequency

Shaft frequency, which is an essential feature of different vessel targets, possesses a crucial application value to the underwater targets detection. Based on the base frequency analysis of target propeller noise with multiple autocorrelation, we propose a one-dimensional fuzzy judgment method to get the credible degree of the base frequency in each base frequency band. Adopting the component of the linear spectrum and its corresponding credible degree threshold of base frequency, the purpose of extracting target’s characteristic base frequency is realized to identify the target. The sea trial results show that the proposed base frequency extraction method based on multiple autocorrelation power spectrum and credible degree threshold filtering of information fusion is effective and feasible in underwater target detection with a detection probability of 92.5%.