Total electron content obtained from ionogram data alone

A method to obtain the total electron content (TEC) of the ionosphere over Tucumán (26.9° S; 65.4° W), from ionogram data alone, is reported. To accomplish this, two Chapman profile expressions for the electron density (n) distribution in the F region are assumed, and a characteristic point of the n profile, called F region base point, is required. This method allows the TEC for a given particular time (not average) to be obtained. The results suggest that it could be a new method to calibrate polarimeter records used to measure TEC, and it could also allow the determination of TEC at predawn hours where only ionosounder data are available.