A new technique for the measurement of the plane-wave reflection coefficient of a horizontally stratified
ocean bottom is described. It is based on the exact Hankel transform relationship between the reflection
coefficient and the bottom reflected field due to a point source. The method employs a new algorithm for
the numerical evaluation of the Hankel transform which is based on the "projection-slice" theorem for
the two-dimensional Fourier transform. The details of the algorithm are described in the companion
paper. Although the algorithm is applied to the case of an isovelocity ocean, the general theory for
measuring the plane-wave reflection coefficient in a refracting ocean is developed. The technique provides
information about the reflection coefficient, not only for real incident angles, _but also for complex angles,
thus potentially providing substantial additional structural information about the bottom. The method is
shown to yield excellent results with synthetically generated data for the cases of a hard bottom and slow
isovelocity bottom.
