  The spherical Radon transform (SRT) is an integral transform that maps a
function to its integrals over concentric spherical shells centered at
specified sensor locations. It has several imaging applications, including
synthetic aperture radar and photoacoustic computed tomography. However,
computation of the SRT can be expensive. Efficient implementation of SRT on
general purpose graphic processing units (GPGPUs) often utilizes non-matched
implementation of the adjoint operator, leading to inconsistent gradients in
optimization-based image reconstruction methods. This work details an efficient
implementation of the SRT and its adjoint for the case of a cylindrical
measurement aperture. Exploiting symmetry of the cylindrical geometry, the SRT
can then be expressed as the composition of two circular Radon transforms
(CRT). Utilizing this formulation then allows for an efficient implementation
of the SRT as a discrete-to-discrete operator utilizing sparse matrix
representation.
