A practical tropospheric scatter model using the parabolic equation

A simple method that accounts for tropospheric scatter using the parabolic equation portion of the radio physical optics (RPO) model is described. RPO is a hybrid propagation model that combines ray-optics and parabolic-equation methods to assess realistic range-dependent tropospheric effects at frequencies from 100 MHz to 20 GHz. A semiempirical scatter model adds a random refractive-index fluctuation to the mean refractive-index value at each height considered by the parabolic equation method. The results of this scatter model are compared with those of another scatter model and with a few sample radio measurements