The Galileo Precise Timing Facility (PTF) – A challenging SW

XX Congresso Nazionale AIDAA – Milano, 2009
The Galileo Precise Timing Facility (PTF) – A challenging SW architecture
A. Bellotti1 and D. Villabruna2
1. AleniaSIA S.p.A., Strada Antica di Collegno 253, 10146 - Torino
[email protected]
2. AleniaSIA S.p.A., Strada Antica di Collegno 253, 10146 - Torino
[email protected]
Abstract (Topic: Space Engineering and Technology)
The Precise Timing Facility (PTF) is a system that generates the Galileo System Time (MasterClock), i.e. the
physical time scale of Galileo.
The “Consorzio Torino Time” (CTT) is in charge of the implementation of the Precise Timing Facility and is
constituted by the industrial and academic partners directly involved in the project, as well as by the
institutional partners Fondazione TorinoWireless and Finpiemonte, all located in Torino, Piedmont Region,
Italy.
The PTF is being developed by the following CTT partners:
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ThalesAleniaSpace Italia, responsible for Management / Technical coordination and overall Design,
INRIM (former Istituto Elettrotecnico Nazionale Galileo Ferraris) and Politecnico di Torino for the
GST Generation Algorithm,
SEPA (Sistemi Elettronici Per l’Automazione) for the Electrical Design and AI&T,
ALTEC for Project Control and Logistics.
Alenia SIA for the design/implementation of the main software application (Control & Algorithms
Software System ) and the SW Product Assurance
CTT is cooperating with the Astrogeodynamic Observatory (AOS, Poland) and with SpectraTime for some
scientifical subsystems of PTF.
The Precise Timing Facility (PTF) is one of the key facilities of the Galileo ground segment.
In order to fulfil this objective the PTF has been designed with a structure similar to a Timing
Laboratory but with the necessary redundancies and control systems in order to be able to
work autonomously.
The system is controlled by a complex software infrastructure developed in accordance with Galileo
Software Standard (as tailored from ECSS E40/Q80,) and based on a dedicated system partitioning
architecture compliant to real time operating systems Arinc 653 Standard.
The software architecture is partitioned in several standalone modules to keep the various functionalities
highly independent in relation to the task and the level of criticality (DAL C and DAL E in this context)
The final paper will recall the major characteristics of the PTF main software application and focuses on the
architecture solutions adopted in the definition and implementation to reach the goals to control a complex
system in terms of scheduling, algorithm batch execution, security, safety and standard compliance.