Wiener filter realization for target detection using group delay statistics

Several techniques are demonstrated for Wiener filter realization based on group delay statistics. The theoretical analysis shows that an inverse relationship exists between the frequency-domain signal-to-noise ratio and the group delay moving standard deviation and/or group delay moving entropy. Therefore, an adaptive Wiener filter can be realized without a priori knowledge of the signal and noise spectra. Group delay statistics estimation algorithms are proposed and evaluated by simulation. Experimental data from ultrasonic flaw detection are presented to support the effectiveness of the techniques