A Monte Carlo model has been used to compute a set of point-spread functions (PSF's) and modulation transfer functions (MTF's) that determine underwater-image quality in a range of different environments. The results have been used to analyze the range of application under which a linear-approximation theory holds. Conclusions of the study are that the linear-approximation theory seems to hold quite well over a broad range of applications. The ramifications of the Wells small-angle-scattering theory that predicts the PSF from a knowledge of the volume-scattering function (VSF) are also considered. Discrepancies are noted between a predicted and a computationally obtained MTF; these discrepancies increase with range. Therefore, the results of the simulations indicate that the small-angle-scattering theory is more valid at a limited number of attenuation lengths. The results of the simulations indicate that the theory is valid to approximately three attenuation lengths.
© 1995 Optical Society of America
Original Manuscript: May 2, 1994
Revised Manuscript: February 7, 1995
Published: August 20, 1995
Jules S. Jaffe, "Monte Carlo modeling of underwater-image formation: validity of the linear and small-angle approximations," Appl. Opt. 34, 5413-5421 (1995)