Determining electron density profiles for the middle ionosphere

Using daytime numerical ionospheric profiles from W. Becker's mid-latitude collection, the geometric parameters of 3 or 4 LAY-functions were determined by best fit while all amplitudes were redetermined step by step with a least squares criterion. It appeared that the transition height and scale of the main function are interrelated while all other geometric parameters are independent. Median values for a spring and a summer period are found, and relations with the peak altitude and half-density thickness of the input profile are established.