Ultrasonic weighted imaging of synthetic aperture focusing technique based on the correlation of signals

A weighted imaging method of an ultrasonic synthetic aperture focusing technique based on the correlation of signals is presented. The correlation between the ultrasonic echo signals within synthetic aperture range is analyzed, and the distribution of the correlativity coefficient is confirmed to parabolic equation in the region of defect echo waves. The signal amplitude correlativity coefficient is defined to describe the probability of a pixel as a non-noisy pixel. Both the two kinds of correlativity coefficient are used as the weight coefficients of weighted imaging methods. As to effective signals and noise signals, the distribution for correlativity coefficient of echo signals implies the identification of the signals and noises, and amplitude correlativity coefficient implies two different processing methods while dealing with them. Theoretical and experimental results show that weighted imaging method can improve the SNR and the lateral resolution of ultrasonic synthetic aperture imaging.