Traveltime based Kirchhoff PSDM common angle gather output scheme

Angle domain common image gathers (ADCIGs) are the basic data for the MVA and AVA. In this paper, a common angle gather output scheme of Kirchhoff PSDM is introduced. It includes: (1) the traveltime calculation is based on the dynamic programming approach adapted to arbitrary medium, (2) obtaining the reflection angle i according to the gradient of traveltime filed in the image space, (3) ADCIGs are extracted in the migration process. We compare the offset domain common image gathers(ODCIGs) of numerical models with the ADCIGs of numerical models. Numerical examples on synthetic data demonstrate the feasibility of the method.