## 4pUW15. Modeling low-frequency surface scatter intensity statistics.

### Session: Thursday Afternoon, December 5

### Time: 4:51

**Author: Eric I. Thorsos**

**Location: Appl. Phys. Lab., College of Ocean and Fishery Sci., Univ. of Washington, Seattle, WA 98105**

**Author: Donald B. Percival**

**Location: Appl. Phys. Lab., College of Ocean and Fishery Sci., Univ. of Washington, Seattle, WA 98105**

**Author: Kate M. Bader**

**Location: Appl. Phys. Lab., College of Ocean and Fishery Sci., Univ. of Washington, Seattle, WA 98105**

**Abstract:**

Low-frequency surface backscattering experiments (CST-7, ASREX) show that
the surface scattered field statistics are non-Gaussian, which means the
intensity statistics will be nonexponential. These data show the intensity
distribution to be closer to log normal. In such cases the statistical
distribution depends on the scattering area on the surface or, equivalently, on
the number of scatterers. An analytical model has been developed for the
intensity distribution that results when the scattering area contains multiple,
spatially independent, identically distributed scatterers. The individual
scatterers, e.g., bubble clouds, are assumed to yield a log-normal intensity
distribution. The assumption that the scatterers are spatially independent leads
to a Poisson distribution for the number of scatterers in a given surface area.
The parameters to be specified are the standard deviation of the log-normal
distribution and the average number of scatterers per unit area. Monte Carlo
simulations yield estimated intensity distributions in very good agreement with
the analytical model. Preliminary comparisons will be made with ASREX data.
[Work supported by ONR.]

ASA 132nd meeting - Hawaii, December 1996