We present a new spotlight SAR data-focusing algorithm based on a two-step processing strategy that combines the advantages of two commonly adopted processing approaches: the efficiency of SPECAN algorithms and the precision of stripmap focusing techniques. The first step of the proposed algorithm implements a linear and space-invariant azimuth filtering that is carried out via a deramping-base...

A function of the auditory system is to accurately determine the location of a sound source. The main cues for sound location are interaural time (ITD) and level (ILD) differences. Humans use both ITD and ILD to determine the azimuth. Thus far, the conception of sound localization in barn owls was that their facial ruff and asymmetrical ears generate a two-dimensional grid of ITD for azimuth an...

Common-azimuth migration (CAM) is an attractive solution for 3-D prestack imaging. It reduces the full 5-D phase-shift operator to 4-D through the stationary-phase approximation, lowering the computational cost. However, this assumption yields constraints in the downward-continuation process that can limit accuracy. Those errors are estimated in this paper by comparison to other wave-equation m...

A practical implementation of azimuth moveout (AMO) must be both computationally efficient and accurate. We achieve computational efficiency by parameterizing the AMO operator with the help of a transformed midpoint coordinate system. To achieve accuracy, the AMO operator needs to be carefully designed for antialiasing. We propose a modified version of Hale’s antialiasing algorithm, which switc...

I introduce a new migration method that overcomes the limitations of common-azimuth migration while retaining its computational efficiency for imaging marine streamer data. The method is based on source-receiver downward-continuation of the prestack data with a narrow range of cross-line offsets. To minimize the width of the cross-line offset range, while assuring that all the recorded events a...

Common-image gathers are an important output of prestack depth migration. They provide information needed for velocity model building and amplitude and phase information for subsurface attribute interpretation. Conventionally, common-image gathers are computed using Kirchhoff migration on commonoffset/azimuth data volumes. When geologic structures are complex and strong contrasts exist in the v...