Abstract:
In some recent experiments conducted at the ARL:UT Lake Travis Testing Facility, acoustic images were created from scattering data of targets with complex geometries. The acoustic measurements were made in the volume in a monostatic scattering configuration at an approximate range of 40 m. The targets were constructed of either fiber-reinforced plastics and/or metals. A variety of large and small bandwidth product waveforms were chosen for the experiments including LFMs, simulated dolphin clicks, and short sinusoidal tone bursts. The frequencies of the waveforms span the range from 15 to 160 kHz. Data were taken by rotating the targets through 360 deg in finely spaced increments about several prechosen axes. The scattering data are processed in several ways. The processed data from different aspects are combined to reconstruct the shape of the object using image processing algorithms based on synthetic aperture and tomographic techniques. By varying the parameters of the incident waveforms, the resulting quality of the acoustic images is examined as a function of frequency and bandwidth. [Work supported by ONR.]