Context

Technical challenges:

Team members from different CS business units since PCF concerns different expertise areas:
orbitography
space mechanics
real-time critical systems
navigation Compliance with ECSS-Q-ST-40C, ECSS-Q-ST-30-02C, ECSS-Q-HB-80-03A standards on Safety with main methods faced:
Functional Hazard Assessment (FHA)
Preliminary System Safety Assessment (PSSA)
System Safety Assessment (SSA)
Fault Tree Analysis (FTA)
Failure Mode and Effects Analysis (FMEA)
Hardware/Software Interaction Analysis (HSIA)
Failure Detection, Isolation and Recovery Analysis (FDIR)
Maintainability Analysis
Common Mode and Common Cause Analysis (CMA, CCA) Compliance with ECSS-E-ST-10C “System engineering general requirements“ for Requirements specification :
The Reqtify tool supports the generation of traceability matrices of requirements and tests between
different documents. The verification of these matrices, through the check of the Reqtify tool outputs,
is part of the verification that top-down requirement allocations and bottom-up requirement verification
are correct, complete and consistent.
The following traceability analyses are conducted:
Coverage analysis of the requirements baseline and software development outputs (technical
specification, design, source code) between them, and production of associated bidirectional
traceability matrices,
Coverage analysis of the requirements baseline and the software development outputs (technical
specification, design, source code) by tests, and production of associated bidirectional traceability
matrices. The results (i.e. bidirectional traceability matrices, as well as any needed justification for instance with
respect to derived requirements) are documented within the Verification Control Document (VCD) and
the Software Traceability File (STF).

CS Group responsabilities for Prediction Chain Facility (PCF) are as follows:

Development, Integration, Qualification and Support for the SoL approval of the PCF

Main Picture

The features are as follows:

Check and pre-process the RIMS observables received for the Prediction chain
Determine the ionosphere corrections and error bounding parameters and ionosphere corrections
Schedule the appropriate SBAS message taking using the bandwidth, TTA, Integrity constraints
Format the EGNOS messages with the applicable standards, using correction parameters computed above
Compute the Quality of Service (QoS) indicator based on the corresponding PCF/ICF computations for the virtual GEO lane
Send the SBAS messages to ICF for verification before provision to NLES

Project implementation

The project objectives are as follows:

PCF is in charge of the computation of the satellite and ionosphere corrections and error bounding prediction parameters, formatting and scheduling of the EGNOS messages and generation of Quality of Service (QoS) parameter.

The processes for carrying out the project are:

V cycle

Technical characteristics

The solution key points are as follows:

Compliance with ECSS-Q-ST-40C, ECSS-Q-ST-30-02C, ECSS-Q-HB-80-03A standards on Safety with main methods faced
Compliance with ECSS-E-ST-10C “System engineering general requirements“ for Requirements specification
Writing of all the Safety and Dependability activities in the Software RAMS Plan

Archi Picture

The main technologies used in this project are:

Domain	Technology(ies)
Operating System(s)	Linux
Programming language(s)	C
Production software (IDE, DEVOPS etc.)	Enterprise Architect, Eclipse IDE, Klocwork, RTRT, Jenkins and Mantis