A new method for impact localization is introduced based on array signal processing technology.A narrowband frequency component of response signal is extracted by using wavelet transform

direction-of-arrival（DOA）is estimated based on propagator method.Based on propagation characteristics of Lamb wave

time-delay between symmetry modal wave and antisymmetry modal wave of one central frequency lamb wave arriving to the same array element is gained by using wavelet transform

distance between impact source and sensor is estimated according to velocity difference between symmetry modal wave and antisymmetry modal wave

so impact localization is realized.The proposed technique is applied to aeronautical tank

the result shows that the proposed method may identify impact location fast and accurately.