Source Direction Angle Gathers

In general, the pre-imaging condition methods for generating angle-domain common-image gathers are computationally expensive. Algorithms that require full or partial wavefield decomposition at every image point prior to imaging produce gathers of high quality but are prohibitively expensive when applied to dense full-azimuth surveys. Direction vector based methods are an attractive alternative to reduce the cost but are often troubled by complicated wavefields that exist in geologically complex areas. In this paper we present a method that reduces the cost of most pre-imaging condition methods and in particular, direction vector based methods while considerably improving their quality. We present the detailed workflow and substantiate our claims with the help of synthetic and real data examples.