Shadow imaging: attenuation projection of acoustic waves from a circular array without arrival picking
David C. Henley
We demonstrate a technique for producing a low-resolution image of an object within the boundaries of concentric ultrasonic circular source and receiver arrays in a water environment. The method does not require arrival picking, and uses the intensity of acoustic arrivals to form "shadows" within the circular aperture. The shadows are subsequently rotated and shifted to properly position them for stacking. The result is a low-resolution "attenuation" image of the immersed object, hopefully suitable for a low-order starting image for subsequent Full Waveform Inversion.