2D Synthetic Emitter Array methodology for improving GPR reflections

In this article, a previously developed 1D-array method is extended to 2D-arrays, and the results of the 2D extension are analyzed and compared to the results of the 1D-array, Common-Midpoint and Single Offset techniques. The proposed 2D procedure considers a rectangular, homogeneous geometry for the array and a simple phase-relation between the component traces. In addition to directing the wave-front towards the target, these settings make possible to reduce the width of the wave-front along both axes of the array, which is expected to enhance the 1D results. Since the dimensionality increases in the 2D geometry, the number of traces in the summation grows significantly, which should also improve the final result. As a part of the 2D methodology, a variable that represents the reflection improvement, with respect to the Single Offset method, is defined and optimized as a function of the phase differences between adjacent traces along both directions of the array and the position of the emitters-receiver group along the survey line. A final data-section is generated from the optimal values found in this step. To evaluate the results of these methodologies, two basic types of reflections are analyzed: diffractions produced by small objects and reflections at extensive interfaces. Numerical and laboratory data are considered. The effects of different numbers of emitters and distances between them on the results are investigated, in order to obtain the best result. The 2D method shows noticeable enhancements of the continuity and amplitude of the primary reflection with respect to the other methods.