P-P And P-SV Wavefield Separation For Three-component Seismic Exploration Data Of Non-cable Self-positioning Seismographs

In three-component seismic exploration, the vertical component of the seismicprofile contains not only P-P wave energy, but also P-SV wave energy. At the sametime, the horizontal component contains both P-SV and P-P wave energy. The con-taminating energy on either component is unfavorable for the following data processingand geological interpretation. Therefore, as a method to extract valuable signals, theseparation of P-P and P-SV wavefields becomes of much importance.P-P and P-SV wavefield separation may be performed in a number of differentways, such as the method of motion product, f-k filtering, polarization filtering, waveequation method and Radon transform method. Among these methods, Radon trans-form method is quite simple and effective, because no detailed P-P and P-SV wavevelocities are needed during the separation process. At the same time, as for processingpractical seismic profiles, Radon transform method has more advantages than othermethods.Due to the differences of parameters like slowness and curvatures, the overlappingtime-domain events can be mapped into different zones in the Radon domain. Mutingthe undesired events in the Radon domain and transforming the remaining signalback to the time domain will lead to separated wavefields. In the past, the Radon-based separation method used to apply the transform (linear transform) for dataprocessing, but in the domain, P-P and P-SV events often overlaps together,which makes it hard to separate thoroughly.On the basis of transform and the three-component seismic data acquired byself-developed non-cable self-positioning seismographs, this paper discusses the sepa-ration of P-P and P-SV wavefields based on parabolic Radon transform and hyperbolicRadon transform. Combined with the traveltime properties of P-P and P-SV waves,the original data can be mapped into different”points” in the Radon domain byparabolic Radon transform or hyperbolic Radon transform, making it easy for P-Pand P-SV wavefield separation. This paper first discusses the reflection and transmis-sion of seismic waves, and analyses the travel time of P-P and P-SV waves. The paperthen illustrates the theory of parabolic Radon transform, discusses the least-squaresparabolic Radon transform, and provides its high-resolution algorithm. The theory ofhyperbolic Radon transform is then analysed. At last, we verify the feasibility of the Radon-based wavefield separation scheme with synthetic records and real data exam-ples, and discusses the advantages, disadvantages and applications between these twoRadon-based separation method.