Digital ray tracing in two-dimensional refractive fields

Abstract

This paper presents a review of digital ray tracing in two-dimensional refractive index fields. Since the refractive index fields are not assumed to have any particular symmetries or other special properties, the reviewed methods do not include the techniques developed in optics and in ocean acoustics. We have assumed general two-dimensional refractive index distributions such as would be encountered in ultrasonic computerized tomography. In this paper we have also reviewed digital ray linking, that is, finding a ray path that connects a given transmitter–receiver pair. Also discussed are the difficulties caused by the discrete representation of the refractive index fields and the different interpolation procedures that have been suggested to get around this problem.