Deducing topside profiles and total electron content from bottomside ionograms Original Research Article

A new technique of estimating the ionospheric topside profile from the information contained in the groundbased ionograms is introduced. The electron density profile above the F2 layer peak is approximated by an α-Chapman function with a constant scale height that is derived from the bottomside profile shape near the F2 peak. The scale height is obtained from the bottomside profile by representing the latter in terms of α-Chapman functions with scale heights H(h) that vary as a function of height. The scale height at the layer peak is then used for the topside profile. The total electron content (TEC) is obtained by integrating the electron density from h = 0 to ∞. The ionogram derived TEC values, ITEC, are compared with incoherent scatter radar, Faraday, and TOPEX TEC measurements showing very good agreement at middle latitudes and the magnetic equator.