Estimation of Photoacustic Signals Using Subspace Identification

This work presents a new estimation scheme for photoacoustic signals and the absorption profiles associated with these signals, based on a discrete linear time-invariant state-space model of the Stokes’ equation, which describes the propagation of ultrasound waves in acoustic attenuating media. Parameter estimation is performed using the N4SID method for subspace identification, taking advantage of discrete model properties. In addition, the gradient descent and regularization method is used to improve parameter estimation. The simulation results validate the scope of the proposed scheme.