Dictionary:Common-scatterpoint (CSP) gather
A collection of prestack migrated traces that involve the same scatterpoint. The maximum offset is limited by the migration aperture and the fold may be large. The gathers, formed with an inaccurate velocity model usually are analyzed by conventional techniques (such as semblance analysis) to yield a more accurate velocity model. conventional NMO corrections, scaling, and stacking of a CSP gather is the same as Kirchhoff prestack migration.