Several types of perturbations can affect the signal processed by a GPS receiver. These perturbations are thermal noise, atmospheric disturbances, multipath and interference. Interference remains the most feared perturbation for civil aviation users because it can affect several tracking channels at a time during a long period. This is a serious problem since it can first affect the continuity of the navigation service and necessitate reversal to other means of navigation or assistance from the air traffic services. Different techniques have been presented to improve robustness of receivers against interference [1] based on antenna, RF front end and/or signal processing module designs [2]. However, if interference is not mitigated by implemented techniques, it can also affect the integrity of the pseudorange measurements. In particular, RAIM algorithms implemented in all aviation receivers to ensure integrity are designed to meet their requirements only when there is a unique failure. The case of interference is therefore not obviously protected by RAIM techniques. For this reason, there is a need to develop a module able to detect and characterize jammers affecting the receiver processing. Such a module would be most helpful if imbedded in the receiver and not requiring any heavy external equipment such as spectrum analyzer. The following paper discusses the use of multicorrelator receivers to achieve such a goal.