Ionogram analysis - least squares fitting of a Chapman-layer peak

Plasma frequency is expressed as a function of real height near a layer peak in order to combine in a single least-squares solution the profile data from lower heights and the scaled critical frequencies from both magnetoionic components. The rms fitting errors for the critical frequency, peak height, and scale height are thus obtained directly from the results. It is noted that with good data the final result is independent of the model proposed, whereas decreasing amounts and consistency of the data will put more weight on the initial (model) scale height in the solution. This, in turn, will reduce the normal tendency of the peak extrapolations to become erratic or absurd as the quality of the data decreases. 10 references