We obtain an explicit and useful formulation of the solution for the second-order Rytov approximation for an arbitrary source geometry. From this solution a condition of validity for the Rytov solution is obtained. We conclude that both the Born and the Rytov approximations have the same domain of validity.
© 1983 Optical Society of America
H. T. Yura, C. C. Sung, S. F. Clifford, and R. J. Hill, "Second-order Rytov approximation," J. Opt. Soc. Am. 73, 500-502 (1983)