An experimentally based investigation on the refinement and development of mid-latitude trough models over Europe-description and initial measurements

A new experiment to examine the propagation characteristics of radiowaves propagating through the mid-latitude ionospheric trough region has been described. The aim of this new investigation is (a) to determine experimentally the accuracy of the currently available models of the trough by a comparison of ray tracing simulations with measurements of the direction of arrival of a number of HF radio signals propagating through the trough region, and (b) to improve the accuracy of the models by imposing physically realistic refinements to the models to give a better fit to the experimental data. Example measurements have been presented that reveal important information about the propagation characteristics of the signal