This book contains a comparison of predicted total electron content using two international reference ionosphere models IRI- 2012 and IRI- 2001 with observed values obtained from Athens ionogramsin order to know the accuracy of the models for predicting the total electron content over Iraq since Athens lies in a latitude close to that of Iraq. It is found from the tables and figures of the results presented in this book that the IRI- 2012 model is more accurate than the IRI- 2001 model for predicting the total electron content over Iraq.