Residual migration can be used for both image improvement and velocity analysis. As was previously shown Biondi and Sava (1999), we can use the differences between a given image and an improved version of it in wave-equation velocity analysis. Since full 3-D prestack velocity analysis using the wave equation is still not within reach owing to its huge computational cost, the common-azimuth approximation seems to be the proper technology usable for 3-D datasets. It is therefore necessary to devise the appropriate residual migration tools for common-azimuth data.

In the first part of this short note I present the derivation of the common-azimuth Stolt residual migration equations, followed in the second part by a simple synthetic example.

10/25/1999