In this work, a comparison between soil moisture products derived from satellite and land model data was performed; in particular, the soil moisture retrievals of SMOS and ASCAT were compared with those of the ERA-Interim/Land model, produced by the ECMWF in a timeframe of 3 years. Subsequently, for a limited period of time, the product from the SMAP radiometer was joined to SMOS, ASCAT and ERA-Interim model data as a fourth dataset. In both cases, the whole H-SAF region of interest, which includes Northern Africa and Europe, was analysed. In order to validate the products, the Triple Collocation technique was applied to estimate the independent error standard deviation of three systems that observe the same target parameter. When more than three datasets were available, the Quadruple Collocation technique was used to jointly estimate the error standard deviation of four sources. Moreover, when the SMOS and SMAP radiometer products were considered, the Extended Collocation was adopted in order to evaluate the error variances of the systems, taking into account the possible presence of an error cross-correlation between the radiometer retrievals.