Advanced Receiver Autonomous Integrity Monitoring (ARAIM) is an evolution of RAIM, developed to exploit the benefits of dual-frequency, multi-constellation. The ARAIM concept was initially developed to serve the aviation community. The European Commission (EC) is looking into the exploitation of the concept by other sectors. This paper focuses on the modelling of the local errors, in order to use of the ARAIM concept for three specific sectors: rail, maritime and UAVs.

This paper further develops the high-level evolutions proposed in the previous project ARAIMTOO for the three sectors:

• _{For Rail, combination of SBAS with ARAIM, plus hybridization with IMU/Odometer.}
• _{For Maritime, an ARAIM solution based on multiple antenna processing in combination with SBAS.}
• _{For UAVs, combination of PPP with ARAIM plus hybridization with IMU.}

Aspects relative to integrity concept, including the definition of the architecture and the user algorithm, as well as a proposed tailoring of the Integrity Support Message, will be discussed. It then focuses on the characterization of the local effect models for multipath and Non-Line-Of-Sight (NLOS), by means of real data campaigns. In this respect, the Experimentation described in the paper includes results from the processing of GNSS real data. Finally, future work on the use of these models to perform the proof-of-concept of the proposed ARAIM evolutions will be discussed.

As will be shown in this paper, accurate and reliable local error models can enable the use of ARAIM beyond aviation, meeting the requirements of different applications within the Rail, Maritime and UAVs sectors.

The work is performed in the frame of the Horizon Europe project ARAIMFUSE (Advanced RAIM for Rail, Maritime and UAS) project, led by GMV and funded by EC.