MARGAL Prototype Demonstration - Inland Waterways Applications Results The following items were observed: EGNOS corrections was received by the reference station New correction messages based on enhanced RTCM were transmitted by the base station. New correction messages was received by the on board equipment, processed and used by the onboard equipment. AIS based EGNOS correction was received even if the line of sight to (all) satellites was obstructed. Inland waterway AIS protocol used during the trial. Fixed structures like bridges will disturb the normal operation since the view to all satellites was obstructed. This was normally for a short period of time (less than 30 s). Figure 1: DPS screen Figure 1 illustrates a passing under a bridge. The lower left part of the screen shows indicators for direct and indirect reception of EGNOS corrections. Both links are up and running. On the upper right hand the "satellites in view" show only 3 valid satellites. The other satellites are either obstructed by the bridge or not monitored by EGNOS. As a result the geometry is poor and the estimated position accuracy is 2.3 meters instead of the normal 1.5 meters. During the passing the accuracy will exceed the alarm limit of 2.5 meters (set for this demonstration). In summary all the elements designed in the MARGAL project performed according to design specifications. This was also ensured by the SAT procedure.