LAUSR

This work presents two variants of Born-series methods, for the first time, providing a numerical solution to the time-independent photoacoustic wave equation. These methods are effective in providing accurate solution even when there is a mismatch in speed-of-sound between the source and the ambient region. The traditional Born-series (TBS) and convergent Born-series (CBS) methods have been systematically compared for a test imaging case. The solution was computed keeping speed-of-sound outside the source as constant (1500 m/s) and varying the same quantity from 1950 to 1200 m/s inside the source (a disc with 5 μm radius) over a large frequency band (7–2000 MHz). The TBS method fails to converge when the variation in the speed-of-sound is approximately % or %. The CBS method provides the required robust numerical solution even in case of mismatch in speed-of-sound in various regions of imaging domain.