Application of Ocean Acoustic Tomography in Shape Reconstruction of Underwater Objects

Underwater surveillance and sensing is generally based on acoustics i.e. Sonar. This paper presents the application of acoustic reflection tomography methods for reconstruction of reflectivity of the underwater objects in active sonar environment. Based on the physical optics approximate, and by exploiting the relation between ramp response and the profile function in the illuminated region of the object, the profile function is obtained by time frequency analysis,. The study indicates that fairly good profile function can be obtained by application of time frequency analysis methods using limited frequency domain data. Reflectivity of the object is computed by applying tomography technique on the profiles obtained from the acoustic data, reflected by the object. These results obtained are found to be sufficient for visual identification /classification of the underwater objects.