Ultrasonic Transmission Speckle Imaging

Speckle interferometry, as developed during the past decade for optical astronomy, is adapted to ultrasonic imaging through water and animal tissue. Experimental results are presented illustrating not only Labeyrie's original idea, but also speckle holography and our recently devised shift-and-add technique. Both incoherent and coherent processing are investigated (only the former is feasible in astronomy since the sources are spatially incoherent). The results demonstrate that image quality can be improved dramatically when coherent processing is used.