| Abstract: | Ultrasonic CT has been applied to thermal environmental measurements as a kind of nonintrusive method. This research tries to develop a new ultrasonic CT reconstruction method to deal with problems such as having not enough projection data due to limited projection angle. The new CT reconstruction algorithm is based on inverse matrix transformation which differs itself from the ordinary CT reconstruction, known as FBP(Filtered Back Projection) with SL Filter. In current paper, 3 kinds of iterative CT reconstruction algorithms are described. Computer simulations were conducted to verify the above algorithms and the reconstruction results were compared. An experiment on 3D temperature distribution measurements was carried out to validate the proposed algorithms. According to the simulation and experimental results, improved CGM (Conjugate Gradient Method) taking consideration of regularized least squares was suggested to be the optimum iterative way for CT reconstruction under the condition of limited projection angle. |
