Azimuth depending multi-component receiver coupling to the seafloor

Summary Measured receiver differences on both horizontal receiver components are quite common in the offshore environment and are often caused by receiver coupling to the seafloor. In order to explain this behavior, we consider distinct coupling parameters for both horizontal receiver components. We combine these coupling parameters with the azimuth angle between an airgun shot and the receiver and use two visualization methods, based on correlation and root-mean-square (RMS) amplitudes, to show spatially dependent receiver coupling. We present field data together with simulation results and we find that the field data show an azimuth dependent response pattern which we can reproduce with our simulations. Our hypothesis of azimuth dependent receiver coupling gives an explanation for why vector fidelity tests using airgun shots with 45 degree azimuth angle will not provide information about receiver coupling. The approach we present provides an explanation to the common observation of dissimilar horizontal receiver measurement responses.