For limitation of the matched filter method in underwater acoustic detection,a method of underwater acoustic weak signal detection based on time series characteristic quantity is proposed．Chaotic waveforms, which have thumbtack type ambiguity function, is selected as the waveform of active sonar in the situation of High Dynamic Doppler Frequency Shift. According to the change of correlation dimension while chaotic radar echo appears in the chaotic background, chaotic radar echo is checked out by the means of simulation in the situation of high dimensional chaotic background and low dimensional chaotic background．The method proves out in high dimensional chaotic background．
A New Detecting Method for Underwater Acoustic Weak Signal Based on Differential Double Coupling Oscillator
