Continuous-wave Ultrasonic Tomography In the Presence of Relative Motion of Some Particles within the Rotating Body

Abstract

Continuous-wave ultrasonic tomography is an imaging technique used to obtain information about the structure of deep-lying layers of a certain rotating body. In recent research, the analysis of this tomographic technique is introduced. In this paper, it was assumed that the rotating object is a rigid body, i.e. all particles of this object have the same amount of angular motion and accordingly, all these particles deliver Doppler signals whose frequency depend only on their distance from the axis of rotation. However, If the rotating body includes particles that can move relative to the rest of the body, then the net Doppler frequency shift resulting from the rotation of such particles will not be imaged in their true position, i.e. they will be either too far or too near to the axis of rotation. This effect can be considered as an error in the imaging process. In this paper, this problem will be discussed and suggestions will be introduced in order to avoid this error.