Estimation of the Primary PS Wave Response in OBC Data Using the Receiver Function Approach

摘要

Multi-component recordings provide informations on both the P and S wave structure of the subsurface but most of the methods are developed for the P waves. It is necessary to develop new techniques to isolate the PS wavefield from mixed components. In OBC data, it is also necessary to remove the water multiples to improve the sub-seafloor image quality. Here we propose to use the Receiver Function (RF) method to achieve these two objectives. The RF approach is a powerful method employed in earthquake seismology to compute the primary PS wave response generated in a target zone below a receiver and is based on the use of deconvolution or equivalently adaptive subtractions between components. Our version of the RF approach consists of a multi-step procedure that firstly extract the PS wavefield and next remove the water multiples from the original Ux component, in the -p domain. Our process also gives the geophone calibration filters and the shear wave velocity at the receiver level as additional outputs. The strategy has been successfully applied on a real OBC dataset.