In 2011, the Safety of life Satellite Based Augmentation Systems, i.e. the Wide Area Augmentation System (WAAS) in North America and European Geostationary Navigation Overlay Service (EGNOS) in Europe have undergone significant performance degradations due to an increase in the solar activity. As a matter of facts, the increased solar activity has led to a stronger-than-usual spatial variability of the ionosphere electron content. This required evolutions of the ionosphere algorithms of both systems to recover nominal performance. In the wake of these evolutions, we have studied a number of alternative methods to estimate and map the ionosphere electron content, in a way that could be useful in an SBAS. After a review of the state of the art and of the limitations of the existing methods, this paper presents the comparison of the performances of three of these methods, namely the TRIN model, the Kriege estimator and the Adaptive Normalised Convolution, obtain by processing real-life data sets. These methods react differently to the dynamics of the ionosphere, resulting in different levels of performances. The results are discussed in front of the different conditions in which the system might have to operate. First, a brief survey of each method and their applications in the context of ionosphere interpolation is presented. In a second step, results that summarize the performances observed in a dedicated experimentation are provided. Finally, a discussion and a conclusion are proposed that aim to identify the method that provides the best behavior in nominal and disturbed ionosphere conditions.