Distorted-wave born and distorted-wave rytov approximations

Abstract The relation is considered between the distorted-wave Born (DWB) and the distorted-wave Rytov (DWR) approximations. Analyzing the Helmholtz equation, it is shown that the formal asymptotic justification of DWB and DWR approximations remains the same as that of the ordinary ones. A relation is derived between the first DWB and DWR approximations and an example given to emphasize that these approximations, though simply related, have quite different ranges of accuracy.