Ionospheric profilers using data grids

Most of the empirical ionospheric models which use maps of ionosonde parameters can be considered to be “profilers” in the sense that they use “anchor points” (e.g., E, F1 and F2 peaks) and provide the height profile of electron density between the anchor points and for the topside of the F layer. We present a modelling approach which replaces the global or regional maps (e.g., the ITU-R maps) by data grids and two dimensional third order interpolation for geographic locations between the grid points. The width of the data grids in latitude and longitude can easily be adapted to the intended use of a profiler, e.g., combination of smaller scale structures with a smooth background. The data grids can be constructed entirely from measured data but also from a combination of maps for monthly averages with measured data. In the latter case it is necessary to use buffer zones around the areas where measured data exist to ensure a smooth interface with the outside grid. We demonstrate the data grid method with several different profilers, especially with the “family” of ionospheric models developed at Graz and Trieste.