Characterization and modeling of synthetic aperture sonar imagery.

Abstract

The characterization and modeling of synthetic aperture sonar (SAS) image statistics are of importance for developing target‐on‐background detection and classification algorithms and for developing specialized filters for speckle noise reduction. A simple model is presented to predict the impact of amplitude scaling caused by seafloor ripples on SAS image speckle statistics. The continuous variation in scattering strength produced by ripples (i.e., ripple‐induced changes in seafloor slope) is treated as a deterministic amplitude scaling on image speckle produced by the SAS imaging process. Changes in image statistics caused by ripples are quantified in terms of an effective K‐distribution shape parameter. Agreement between shape parameter estimated from the scaling model and from SAS data collected in experiments off of Panama City, FL and off of the Ligurian coast of near La Spezia, Italy illustrates the efficacy of the model. [Work supported by ONR Grant Nos. N00014‐04‐1‐0013 and N00014‐06‐1‐0245.]