On the simulation of backscatter ionograms

An algorithm for the simulation of backscatter ionograms is developed. Propagation is evaluated by numerically ray tracing through an ionosphere consisting of Chapman layers (major layer parameters derived from CCIR and URSI maps). Simulations are performed for a variety of model ionospheres (including some with strongly varying horizontal structure such as the equatorial anomaly) and are found to reproduce many important features of real ionograms. The algorithm includes backscatter from field-aligned irregularities and this mechanism is found to make substantial contributions to auroral backscatter. (C) 1997 Published by Elsevier Science Ltd.