Geophysical Prospecting, 2008, 56, 327–340 doi:10.1111/j.1365-2478.2007.00685.x Receiver function method in ref lection seismology Pascal Edme 1 ∗ ,† and Satish C. Singh 2 1 Schlumberger Cambridge Research, Madingley Road, High Cross, Cambridge CB3 0EL, UK, and 2 IPG, Laboratoire de Geoscience Marines, 4 Place Jussieu, 75252 Paris Cedex 5, France Received January 2007, revsion accepted October 2007 ABSTRACT The receiver function method was originally developed to analyse earthquake data recorded by multicomponent (3C) sensors and consists in deconvolving the horizon- tal component by the vertical component. The deconvolution process removes travel path effects from the source to the base of the target as well as the earthquake source signature. In addition, it provides the possibility of separating the emergent P and PS waves based on adaptive subtraction between recorded components if plane waves of constant ray parameters are considered. The resulting receiver function signal is the local PS wave’s impulse response generated at impedance contrasts below the 3C receiver.We propose to adapt this technique to the wide-angle multi-component reflection acquisition geometry. We focus on the simplest case of land data reflec- tion acquisition. Our adapted version of the receiver function approach consists in a multi-step procedure that first removes the P wavefield recorded on the horizontal component and next removes the source signature. The separation step is performed in the τ − p domain while the source designature can be achieved in either the τ − p or the t − x domain. Our technique does not require any a priori knowledge of the sub- surface. The resulting receiver function is a pure PS-wave reflectivity response, which can be used for amplitude versus slowness or offset analysis. Stack of the receiver function leads to a high-quality S wave image. INTRODUCTION Multi-component seismic data contain richer information about elastic parameters of the subsurface than the conven- tional single-component data recorded using a streamer or a vertical component array. This is because the horizontal com- ponent data contain converted S-waves. Therefore, a joint analysis of P and S wave data provides important informa- tion on subsurface parameters such as lithology (Tatham and McCormack 1981), porosity (Garotta, Granger and Gariu 2002), fracturing (Ata and Michelena 1995; Li 1997) and anisotropy (Lynn, Simon and Bates 1996; Tsvankin and Grechka 2002; Thomsen 1999) and hence multi-component data are of great importance for the oil and gas exploration industry, and are especially suitable in regions where P-wave ∗ E-mail: pedme@cambridge.oilfied.slb.com † Formerly at IPG, Paris, France imaging fails. For example, when P-wave imaging is affected by strong attenuation due to the presence of gas and results in ‘blind’ zones (for example, a reservoir below a gas cloud), the PS wave imaging method has proven to be an efficient alternative tool (Granli et al. 1999). A key point in multi-component acquisition and processing techniques is the possibility to separate the recorded wave- fields into pure P and S wavefields. It is often assumed that the vertical U z component contains principally pure-mode P wave arrivals and the in-line horizontal U x component con- verted PS wave energy. This assumption becomes invalid at large offsets, where amplitudes of P-to-S conversion are max- imum. Except at vertical propagation, the incident P and S wavefields energy is partitioned between the vertical U z and horizontal U x sensors: U z = U P z + U S z , (1) C  2008 European Association of Geoscientists & Engineers 327