This paper presents a study performed for the detailed analysis of user domain and pseudorange integrity on Satellite
Based Augmentation Systems. Experimental data of EGNOS pre-operational service was used for some specific tests,
aiming at identifying for instance the good reaction of the EGNOS check-set subsystem and the way pseudorange errors
are translated into the user domain. From this analysis, a new technique for User Domain Integrity Assessment (UDIA)
was developed.
With the UDIA technique, the integrity is checked for all possible geometries from 4 to all satellites in view from a
network of stations. When no MI is found (from a wide and sufficiently dense stations network), it can be assured that
the system is safe, and it becomes the best experimental guarantee at the User Domain Level. If a NMI/MI appears from
any geometry of satellites from the stations in the network, thence a search algorithm is applied to identify the satellite,
or combinations of satellites, responsible of such NMI/MIs (i.e., their exclusion leads to the disappearance of the
NMI/MIs). After identifying such satellites, the reaction of the EGNOS Check Set (CS) is evaluated by checking if they
were set as DU or NM within a predefined time interval after the NMI/MI is detected.Peer Reviewe
