Simultaneous reconstruction of temperature and velocity fields using nonlinear acoustic tomography

Acoustic tomography developed and investigated before can only recover either the temperature or the velocity field from the time-of-flight measurements along a single direction of sonic rays. However, the sonic propagation time is a nonlinear function of temperature and velocity; thus, in principle, the measurements allow us to reconstruct both simultaneously. In order to achieve this, we propose a modality of acoustic tomography based on the recently proposed concept of nonlinear tomography, which can take full advantage of the aforementioned nonlinear dependences. Proof-of-concept numerical demonstrations are presented using representative two-dimensional temperature and flow velocity phantoms. The obtained simulative results confirmed the feasibility of nonlinear acoustic tomography in recovering the distributions of temperature and velocity fields.