The effect of topography on the wavelet response of seismic arrays

Abstract

Analyzing seismic arrays using their responses to wavelets provides a more convenient and direct method of analysis than using their conventional time-harmonic responses. In this study, the effect of topography on the wavelet response of seismic arrays is investigated using an approach similar to that of Gangi and Benson (1989). The parameters investigated in the study are: the number of elements (24 and 48 elements), the weighting function (equal and triangular), the incident wavelet (Ricker and Klauder), and the error amount (2%, 10%, and 20% standard deviations). The errors are assumed to be stationary, Gaussian random errors. The degradation in the root-mean-squared (RMS) amplitude response of the array generally increased with the error amount and the number of elements. Errors affected triangularly weighted arrays more than equally weighted arrays, and Klauder-wavelet array responses more than Rickerwavelet array responses. The effect of errors in the elements elevations decreased with increasing incidence angle, while the effect of errors in the elements positions increased with increasing incidence angle. Hence, errors in the elements elevations distorted the seismic signals (which arrive at very low incidence angles) more than errors in the elements' positions did.