To: “Straightforward derivation of Hubral’s wavefront curvature differential equation in inhomogeneous isotropic media,” May 1980, GEOPHYSICS, p. 964–967.

Abstract

The author of the Short Note, “Straightforward Derivation of Hubral’s Wavefront Curvature Differential Equation in Inhomogeneous Isotropic Media,” Th. Krey, has forwarded the following changes to his paper which appeared in May Geophysics, p. 964–967. In equations (19) and (20), [Formula: see text] should be replaced by [Formula: see text]; and in equation (21), C is replaced by (C/v). In equation (10) the product [Formula: see text] is replaced by [Formula: see text]. The last sentence ahead of the “acknowledgement” paragraph should be replaced by the following: The third term appears only if the velocity is a nonlinear function of x, y, z.