SAPET - SATNAV Performance Evaluation Tool

GNSS performance prediction tool - Simulating GNSS satellite performance against terrain influence and aircraft attitude

Air Navigation departments need to evaluate performance of a Global Navigation Satellite System during flight planning and GNSS procedure design pre-validation. SAPET allows the user to evaluate GNSS performance with RAIM computation taking into account terrain, electromagnetic and aircraft masking angles.

SAPET is an add-on package for the IDS flight procedure design system (FPDAM). SAPET is very useful for Aviation Agencies, ANSP (Air NAvigation Service Providers) and aircraft companies deputed to one or more of the following tasks:

• GNSS Procedures and flight planning
• Satellite required navigation perfomance (accuracy, availability, integrity and reliability) analysis

SAPET is able to simulate the performances of Global Navigation Satellite Systems (GNSS) in terms of satellite geometry, terrain influence and aircraft trim. The simulation can be performed over a single location point, wide area, service volume or along a flight track. The system takes into account the satellite constellation used as stand-alone or in conjunction with Satellite-Based Augmentation Systems (ABAS, WAAS, EGNOS, MSAS etc).
In the typical configuration SAPET is connected to the Aeronautical Database (IAS AeroDB) and integrated with FPDAM and the EMACS system for electromagnetic analysis. The integration with FPDAM and EMACS allows easy access to aeronautical features/terrain/procedure database, and support for flight protection limits analysis/verification and EMI multi-path verification.

SAPET Details

SAPET executes the satellites constellation propagation in ECEF coordinates using the almanac in YUMA/SEM format (provided by US Coast Guard via the internet, and taking into account NANU messages.
SAPET evaluates the satellite visibility, the DOP values (X, Y, Z, Precision, Geometrical etc) and the outage due to RAIM and can generate a predictive NOTAM taking into account the constellation parameters, terrain masking, antenna masking, aircraft optical masking and attitude of the aircraft (for flight procedures and restrictions analysis).
Computation is executed according to the RTCA/DO-208, RTCA/DO 229C and ICAO PANS-OPS Doc. 8168 and with the requirements from JAA - Temporary Guidance Leaflets.
SAPET executes:

• GEO constellation propagation using Inmarsat almanac
• Service volumen prediction
• Satellite visibility analysis (with or without GPS augmentation) and contact time
• DOP analysis and statistics
• Accuracy, Availability and Integrity analysis
• Service outages prediction in a point and NSE along flight track
• NOTAM text file generated and stored into database via ODBC connection
• Scheduling capabilities