An Automatic Ionogram Scaling Technique based on the Nelder-Mead method

The work describes an approach to automatic ionogram scaling, suitable for both bottomside and topside sounding. The algorithm is designed to be used on high-perfomance parallel computing servers. It employs ionogram modeling by simulating radio wave propagation in plasma layers and adjusting the parameters of the layers by Nelder-Mead algorithm until the optimal coincidence with the results of sounding is achieved. The validation of automatic scaling was carried out for F2 layer critical frequency (f o F2) by comparison with the data sequence for all previous observation years for a given station. The f o F2 deviation quantiles were calculated for different geomagnetic activity levels. An ionogram’s automatic scaling was considered a failure if the result fell in the lowest 0.01 or the highest 0.99 quantile.