Ultrasonic phased array inspection system is used to test carbon fiber composite experiment panels which contain three kinds of defects such as crack, inclusion and delamination. The collected signals of defects are analyzed by wavelet packet transform. The measure of separability based on distance is proposed as the criterion of evaluation of the wavelet bases to determine the optimum wavelet base. Then the signals of three types of defects are decomposed and reconstructed by wavelet packet transform using...