Temperature measurements using US tomography: Theoretical aspects
Résumé
Theoretical aspects related to the reconstruction of a thermic object from ultrasonic waves are discussed for the case of spherical model (two middles) with two differents refractive indices. A reconstruction technique using the Fourier diffraction theorem and Born's or Rytov's approximations is described. Results obtained by simulation are presented and the feasability of thermographic application is discussed. It is shown that the method is suitable for the determination of temperature from the amplitude and phase variations. It is very sensitive to the refractive index temperature dependence. Good agreement between theory and measurements is demonstrated.