Our comments (Geophysics, October, 1969, p. 793) on the paper of Lacoss et al were not concerned with possible semantic misinterpretation (see authors' response in same issue) on our part of the authors' usage of the term ‘phase velocity,’ but with whether or not the formulas given by the authors are correct. The authors explicitly state (p. 21) that P(kx,ky,f) is the “frequency?wavenumber power spectral density,” so that kx, and ky are components of wavenumber; on page 22, line 3, vx and vy are explicitly described as “phase velocity components.” Then equations (3) and (5) as given by the authors are simply incorrect: Correct equation reads: Equation (3)
Lacoss et al have
This content is PDF only. Please click on the PDF icon to access.