Active Multichannel Analysis of Surface Waves with Non-straight Line Geophone Array

Active multichannel analysis of surface waves (MASW) requires sensor placement along a straight line with equal spacing to predict the properties of sub-surface earth. However, due to the presence of different obstacles in the field, placing sensors along a straight line is not always possible. To this end, the primary objective of this study is to propose a non-straight line receiver array-based active MASW method. The proposed method follows a diverted path near the obstacle while keeping the rest of the geophones in a conventional straight line before and after the shift. Sensors are shifted on an arc of a circle, with the source acting as the center of this circle. Therefore, the distance between the source and shifted sensors remains the same as their original position. This simple maneuver enables us to use existing wavefield transformation techniques without any modification. Multiple field experiments are performed using different non-straight line arrays. Dispersion images obtained from the proposed method resembled the outcomes of a conventional active MASW survey.