Canonical cylindrical target acoustic backscattering investigations

Abstract

In littoral environments where visibility can be low and objects of interest are often either partially or fully buried with respect to the water-sediment interface, the task of identifying unexploded ordinances (UXOs) is a challenging one. Downward looking sonar (DLS) systems have been shown to be capable of penetrating the seafloor of various littoral environments and therefore could be an effective tool for searching for UXOs. However, although DLS’s can penetrate the seafloor, classification and identification (C&I) of targets of interest versus clutter are still a technical obstacle of interest. To address this, researchers at the Naval Surface Warfare Center Panama City Division (NSWC PCD) have been working on algorithms that can identify an object based on its acoustic backscatter response. The concept is similar to identifying the material composition of an object with optical spectroscopy but in this case using the acoustic response rather than the optical spectra. Initial investigations, analysis, and algorithm development have focused on the analysis of acoustic backscattering measurements conducted on various targets in the free-field using linear frequency modulated (LFM) interrogation pulses. Experimental measurements are compared with model results derived from a paper by Lecroq [1]. Data/model results as well as a process for potentially aiding automatic target recognition development will be discussed in this presentation. [1] F. Lecroq, L. Fernand, D. Décultot, and G. Maze, J. Acoust. Soc. Am. 91, 1388 (1992).