Abstract

The enhancement effect of the backscattered intensity in a random medium, continuous or discrete, has been observed when multiple scattering is significant. In the past in theoretical studies a point source was always assumed. In this research, a laser or maser beam is used for the incident wave. The dependence of the enhancement effect on this beam size in a turbulent medium is investigated. To this end, the path integral technique and the conception of propagator are used. The statistical saturation is assumed to be reached in a one-way trip between the transmitter and target. In describing the random structure of the turbulent medium, two power spectrum functions are considered: Gaussian and Bessel-function spectra. The Gaussian one, although perhaps not realistic, produces a simple analytic result and provides some insight. The one with Bessel functions, which can be reduced to a power-law spectrum, gives better descriptions on the turbulent structure; however, it produces more complicated mathematics. The results based on these two spectra are compared and discussed. The result due to a point source can be recovered by taking the limit of small beam size.

© 1987 Optical Society of America