A new estimating method for observing the electron density profile with peak and valley by using the ray path method

Ionograms provide the main source of information about the electron density profile in the ionosphere. Some procedures have been presented for the cal culation of real height profiles from ionograms. However, they usually have unacceptable errors within the valley layer of the electron density profil e. In this paper; we derive a new estimating method which measures the elec tron density profile from propagation delay times. In order to verify the a pproach, the numerical experiments, which are carried out by taking the inv erse fast Fourier transform of the reflection coefficient, are adopted Acco rding to these results, it is possible to estimate the electron density pro file in a one-peak profile within 1.5% errors, including the valley layer. The results show that our method gives a very accurate electron density pro file.