An empirical relationship between ionospheric equivalent slab thickness and mean gradient of the electron temperature in the f-region

It is shown that it is possible to define an empirical law between ionospheric slab thickness and mean gradient of the electron temperature in the F-region. This law is obtained by using data of the incoherent scatter of Saint-Santin (France) and can be used under certain conditions in connexion with ionograms to find the electronic temperature and density profiles above the ionization maximum level.