Coherent noise attenuation in the radial trace domain: introduction and demonstration
David C. Henley
The radial trace transform is a simple mapping of seismic data from the familiar horizontal distance and travel time (X-T) domain of trace gathers and stacked sections to the domain of apparent velocity and travel time. The transform has properties that make it well-suited for such practical applications in seismic processing as wavefield separation and coherent noise attenuation. We describe here the transform and its practical implementation, including aliasing considerations, and we demonstrate linear noise attenuation on both model data and field data using a set of ProMAX modules which we have developed to apply R-T domain techniques.
Radial trace (R-T) domain filtering techniques are distinguished by their focus on localized events in the X-T plane rather than widespread families of events with common frequency and/or wavenumber characteristics as in F-K (frequency and wavenumber) domain methods. A number of successive radial trace filter passes can be applied to X-T trace panels, each pass designed to attenuate one or more specific events. Furthermore, the radial trace transform can be applied to panels with highly irregular X intervals, unlike the F-K transform. This makes the radial domain very attractive for filtering coherent noise on 3-D shot gathers, with their non-linear distributions of source-receiver offsets, since the data need not be interpolated to a uniform offset grid prior to filtering, as with F-K filtering.