In view of the chararcteristics of single-impulse short-echo Doppler sonar

a multi-resolution analyses method is presented based on wavelet transform.By using threshold decresasing noise

Doppler sonar’s frequency excursion can be estimated precisley with Daubechies wavelet function.The simulation resultes show that the scale of wavelet transform is increased to bring the boundary error decreasing and the filtering effect improving remarkably.The result with Daubechies waveler function in 4th scale can meet the required performance of high accuracy inertial navigation systerm（INS） and the velocity of the Doppler sonar makes error of the integer system’s velocity less than 0.2 nmile/h.