A simple, two-dimensional ray tracing scheme is developed and is appli
ed to several propagation problems of importance to over-the-horizon r
adar. In particular, it is used as the basis of schemes for the simula
tion of oblique and backscatter ionograms. The efficiency of the schem
e makes it ideal for applications where fast calculations are required
, and an algorithm for inverting backscatter ionogram leading edges is
developed as a particular example.