A paper co-authored by Bold in 1986, showed evidence that when a system is broken down into its compositional parts, (top down approach) ray tracing is accurate and easy to apply. The authors note that compared to a more traditional approach of mixing rather than isolating the steps in the process, the top down approach using computing power has the potential to develop knowledge of "powerful integration subroutines...[and]...their extraordinary accuracy makes the payoff worth the effort expended in understanding their use." In 1981 Bold collaborated on a project that explored an improved model at the time, for getting better ray calculations by using bounded beams to modify ray paths with a uniform sound speed profile in the Pekeris channel. The authors concluded that this can affect the eigenray yields, [and appeared] "to be as good as normal mode theory for practical calculations in shallow water".
