ECLAYR collects web data of GPS/GLONASS navigation information and the SBAS messages broadcast a few days ago to estimate the satellite positions. On the other hand, it downloads IGS and IONEX files which are considered as "True" Satellite Orbit, Clock and Ionosphere references.

ECLAYR computes errors in pseudo-range and user domains using the web data: SREW (Satellite Ranging Error at Worst user location), GIVDerror (Grid Ionospheric Vertical Delay Error) and Position Error (HPE and VPE). It also calculates UDRE (User Differential Range Error), GIVE (Grid Ionospheric Vertical Error) and Protection Levels (HPL and VPL) and compares these boundaries with their corresponding errors and alarm limits to check integrity and availability.

ECLAYR provides SBAS performance information in HTML format, output data files, statistical summaries, evolution graphics, bar diagrams and geographic maps, analysing accuracy, continuity, availability and integrity.

ECLAYR supports Precision Approach phase of flight according to the standard MOPS A and MOPS C of RTCA/DO229 .

ECLAYR runs on low-cost and widely available HW platforms. It is possible to execute ECALYR on any standard PC with a Windows 2000, NT or XP operating system.