The objective of the activity is to elaborate at System level the concept of distributing integrity amongst Ground, Space, and User Segments. The Space Segment monitors refer to a safety-of-life (SoL) on-board integrity determination unit (IDU), while the User Segment monitor refers to an advanced receiver autonomous integrity monitoring unit (V-ARAIM) within the avionics.

Current single-frequency Satellite Based Augmentation Systems (SBAS) and planned dual-frequency multi-constellation (DFMC) SBAS systems enable approach operations with vertical guidance with time to alarm (TTA) of 6 seconds, but do not support auto land operations with decision height (DH) much less than 200 feet, and time to alarm down to 1-2 seconds . These critical TTA requirements cannot be met by having all integrity monitors centralized at the Ground Segment. Therefore, there is a need to distribute the integrity monitors amongst different Ground, Space and User Segments. The activity is structured in the following tasks: 1. System Function Specification Consolidation. 2. System Function Preliminary Design. 3. System Function Detailed Design. 4. Ground-Segment Monitor Design Performance Assessment. 5. Space-Segment Monitor Design Performance Assessment. 6. User-Segment Monitors Design Performance Assessment. The activity will provide inputs for the safety of life requirements within the European GNSS programmes.