Traveling wave lobe locations

A simple and reasonably accurate formula for the angular locations of traveling wave lobes has been available for many years, but the formula holds only for surface waves that travel at the speed of light. It is shown how the formula may be modified to account for propagation velocities less than the speed of light. It is shown that when the equation derived by the author is used to estimate a starting value for cosQ in the Newton-Raphson method, the solution usually requires no more than three iterations for an accuracy of 10^-6 in the solution for Q