Based On Wavelet Transform Ship Feature

Wavelet transform as a new signal processing method, because it is both in time domain and frequency domain has the ability of denoting local signal information, so the ship characteristic signal has been widely used the wavelet transform in the noise analysis.The ship characteristic signal is mainly divided into ship radiated noise and the water impact weapon launch signals. For ship radiated noise, its linear spectrum due to the transmission distance, small attenuation, contains rich information become the key point of the analysis and research. For water impact weapon launch signals, the time domain impulse is the key point of its analysis and research.Now there are a lot of traditional processing methods for linear spectrum such as Lofar method, the adaptive method, etc. But the ocean background noise is very complex and the rapid development of noise reduction technology, it is becoming more and more difficult to extract linear spectrum. Therefore this paper uses a new research method, namely through the of contact wavelet transform and singularity analyses low Signal to noise ratio of the ship radiated noise power spectrum and the water impact weapon launch signals.This paper, based on the principle of the ship characteristic signal to the maximum extent of approximate simulation, the simulation results of the laboratory and the actual condition in order to achieve as close to as possible. Using the wavelet and singularity analyses the ship characteristic signal of simulation signal, draw the conclusion:1. For the signal of noise ratio is about-20dB(Ship radiated noise of low SNR) the location of the ship radiated noise of its linear spectrum can be detected with singularity.2. For the water impact weapon launch signals, the time domain on the impulse location can be detected with singularity.3. Ship radiated noise power spectrum can use wavelet analysis method for the discrete approximation and the discrete detail.This paper for the first time from a new direction to study the ship characteristic signal and get some meaningful preliminary results. Of course there is much to improve this method, and wavelet transform as a new tool also has many places worth exploring, so the method has certain research value and application potential.