The present project aims to design, implement, and validate a RAIM algorithm with fault detection and exclusion capabilities. It is oriented towards its application in aeronautical navigation as a local alternative to positioning systems that rely on external augmentation services such as SBAS and GBAS, whose coverage is geographically limited. The algorithm has been designed for use in PA and NPA navigation modes supported by SBAS and also implements SPS, employing code measurements smoothed with a Hatch Filter. The algorithm has been developed in Fortran 77 in conjunction with the tool gLAB, which is currently under development by the gAGE research group. This tool has been used for the processing of the datasets and validation of the results. The implementation ensures a suitable computational cost for academic environments. The project workflow has been structured into several phases. First, a critical review of the concept of integrity in satellite navigation is carried out, taking into account the requirements established by ICAO and previous studies conducted by the gAGE group. Subsequently, the RAIM-FDE algorithm has been formulated using the WLS estimator to solve the navigation equations. Protection levels are established by aeronautical standards. The algorithm provides, for each epoch, the system status, including conditions of unavailability or flags for cases that require a missed approach. The validation has been conducted using real GNSS data from permanent stations in the IGS network. Specifically, the NASA Goddard station for the date 10/07/2023, when the so-called Feared Event involving GPS satellite with PRN 1 occurred. This allowed the evaluation of the effectiveness of the algorithm in excluding faulty satellites. Furthermore, a comparative analysis is performed across different scenarios (single/dual-frequency and single/multi-constellation) to assess the capabilities and limitations of RAIM. Finally, economic and environmental aspects related to the development of the project are also considered. The results obtained demonstrate that the proposed algorithm, capable of detecting and excluding faulty satellites, meets the integrity requirements under dual-frequency and multi-constellation scenarios, providing appropriate levels of integrity and availability for en-route applications. However, the scope of this work has been limited to PA, NPA, and SPP navigation modes and does not include advanced techniques such as ARAIM or integration with onboard systems.