Comparison of alignment algorithms for P-Wave coherent averaging

Aim of this paper was to evaluate the performances of 4 alignment algorithms for P-wave coherent averaging. The first algorithm is based on the maximum of the cross- correlation function (CCF) between the current averaged wave and the incoming wave. The second algorithm computes the minimum square error (MSE) between each incoming wave and the current averaged wave. The third algorithm minimizes the difference between the areas of two rectangular window selected on the current averaged wave and the incoming wave (two-windows minimization, TWM). The fourth algorithm finds the local best alignment using the Dynamic Time Warping (DTW). The best alignment algorithm in terms of both shift error and template error resulted to be MSE, for SNR lower than 20 dB. For higher SNR values, MSE, CCF and TWM algorithms showed similar performances. TWM suffers from the necessity to select the two rectangular windows.