A pseudo‐unitary implementation of the radial trace transform

The Radial Trace Transform (RTT) is an attractive tool for wavefield separation because it lowers the apparent temporal frequency of radial events like ground roll, making it possible to remove them from the data by simple bandpass filtering in the RT domain. In Henley’s (1999) implementation of the RTT, the RT domain is wellsampled, and thus suitable for post-filtering, but suffers from interpolation errors because it intepolates across offsets. We present an alternate implementation, which is pseudo-unitary in the limit of an infinitely densely sampled RT space, with the side effect that the RT domain has missing data. Using a simple 2-D filter, we estimate the missing data in the RT domain using Claerbout’s (1998) optimization methodology without affecting the invertibility of the RTT. Our implementation suppresses radial noise while preserving signal, including static shifts.