DMO in the Radon domain

Abstract

A new dip-moveout (DMO) processing technique is proposed. The method is based on an integral DMO method in the Radon domain called Radon DMO, which is especially applicable to irregularly sampled 3-D datasets. Radon DMO offers several advantages for processing surveys with irregularly sampled design or acquisition characteristics, common problems for land and Ocean Bottom Cable 3-D surveys in particular. First, the Radon DMO operator is nonaliased and dealiasing. Missing traces do not cause spatial aliasing, precursor noise, or unbearable distortions of phase and amplitude. Second, Radon DMO does not require that input traces belong to one offset bin. Input traces can be organised from multiple offset bins in the same azimuth grouping to perform Radon DMO. Third, the DMO-corrected output can be either stacked or unstacked, which enables the full range of post-DMO processing including post-DMO velocity analysis. The Radon DMO operator directly maps data from the NMO-corrected time domain to the DMO wavefield in the Radon domain. The impulse responses of Radon DMO are hyperbolas. The method is built upon a process that transforms a single, NMO-corrected trace into multiple traces spread along hyperbolas in the Radon domain. Most integral methods include the application of a 45° phase shift, as well as offset, time, and frequency-dependent gain factors when spreading the traces along ellipses. Such compensations are generally unnecessary with Radon DMO, which greatly simplifies program development and reduces the number of critical elements to control. By eliminating costs associated with gain factor application, the added costs for inverse Radon transform are alleviated. Total costs compare well with conventional integral DMO methods.