On sand ripple detection in synthetic aperture sonar imagery

A model for the detection of sand ripples in synthetic aperture sonar (SAS) imagery is proposed. The approach is based on searching for patterns characterized by three highlight-shadow pairs - corresponding to ripple-wave crests and troughs - at different orientations and at different length-scales. The model also provides an estimate of the orientation of any ripples detected. No training data is required as the underlying physical phenomenon of ripples is modeled directly. The promise of the proposed method is demonstrated on five real, measured SAS images, for which a high probability of (ripple) detection is achieved while maintaining a very low false alarm rate.