Coordinate Conversion Technique for OTH Backscatter Radar

A radio propagation simulation computer program, known as WIMP (World-Wide Ionospheric Modelling Program), has been studied and documented. The purpose of the program is to permit the transformation from Over-The-Horizon (OTH) Backscatter radar coordinates to geographic coordinates, given a vertical incidence and a backscatter ionogram measured at the radar site. The program consists of a three-dimensional ionospheric modelling algorithm, which contains a provision for updating on the basis of the ionograms, followed by a ray- tracing procedure. These algorithms have been deduced from a program source deck and the program structure has been documented in terms of mathematical algorithms and flow charts, together with program listings. The algorithms have been compared with others in use at RADC and quantitative results of this comparison are presented. These consist of ionospheric model comparisons for representative ranges of the model parameters. Finally, a measured backscatter ionogram is simulated, using the RADC program, and the ionospheric structure along the sounder boresight is deduced.