300 likes | 547 Views
The Galileo System - Predicting Performance and Producing Simulated Data for Experimental Purposes. Dr. F rank Zimmermann November 2006. Overview. Introduction Galileo Simulation Capabilities (GSSF) Validation of GSSF Example Results Support to Application Development Summary.
E N D
The Galileo System - Predicting Performance and Producing Simulated Data for Experimental Purposes Dr. Frank Zimmermann November 2006
Overview • Introduction • Galileo Simulation Capabilities (GSSF) • Validation of GSSF • Example Results • Support to Application Development • Summary Technical Excellence . Pragmatic Solutions . Proven Delivery
Overview on Galileo Activities at VEGA • Galileo System Simulation Facility (GSSF) • Galileo Ground Mission Segment Assembly, Integration & Verification Platform (Galileo GMS AIVP) • Galileo Constellation Simulator (CSIM) • Galileo Operations (GSTB V1 & V2, GaIn Operations Manager) • Galileo Test and Development Environment (GATE) • Co-operative Networks for Intelligent Road Safety (COOPERS) • Shareholder of Galileo Centre in Darmstadt (CESAH) (initial) prime objective Application Operations Verification Definition
The Galileo System Simulation Facility (GSSF) Galileo • Independent, global, European satellitenavigation system • For civilian applications & interoperablewith GPS GSSF • Simulation environment that reproducesthe functional and performance behaviourof the Galileo system • Offers the necessary flexibility and functional scope to support Galileo system simulation needs during the entire program life cycle. • Developed on behalf of ESA/ESTEC by an international consortium led by VEGA • Validation has received prime attention (also independently by ESOC). • Visualisation supported by IDL (CREASO)
GSSF – Simulation Capabilities • GSSF provides a single simulator that uses alternative models depending upon the type of analysis the end-user wishes to perform (more flexibility than traditional simulators): • Service Volume Performance Analyses (navigation and integrity performance over longer time periods and over large geographical areas). • Raw Data Generation (Galileo and GPS raw data for experimental purposes: RINEX observation, IGS SP3) • Simulation of the nominal system and its various degraded modes (failures of elements)
GSSF – Model Components • Space Segmentsatellite models • Environmentmain perturbationson satellite signal • User Segmentuser receivers andinternal algorithms • Ground Segmentrequired GS models(GSS & ULS)
GSSF Validation • GSSF has been rigorously validated. • SVS Validation: • Against simulated data from trusted sources • RDG Validation against real data: • RINEX files from Kourou were extracted from the GSTB-V1 test data set together with IGS ephemeris and clock files. • Code, carrier and Doppler measurements as simulated by GSSF RDG were compared with those obtained from the real Kourou data (stepwise approach). • ESA/ESOC have carried out an independent validation of GSSF • Successful IGS Processing and 64 mm RMS orbit fit over 24 hrs • The GSSF Raw Data is a valid representation of real measurement data.
GIOVE-A GIOVE-A GPS • Successful GSSF validation with GPS measurements • GIOVE-A measurements provided by ESA will now be used to further calibrate GSSF RDG • This will not affect the environment but satellite-specific models(e.g. acceleration due to solar radiation). GEO (EGNOS)
Signal in Space Monitoring Accuracy (1) • Nominal SISMAfor Galileo on aGSS network • Representslevel of accuracyin monitoringsatellite positions
Signal in Space Monitoring Accuracy (2) • Nominal SISMAfor Galileo on aGSS network • Subject to twostation failuresover North America • SISMA degradesaccordingly
Ground Station Visibility (1) • Visible GroundStations for a35 Station Network
Ground Station Visibility (2) • Visible GroundStations for aNetwork subject to2 failures • Reduced tominimum of 5 overNorth America
Space Based Augmentation Systems (1) • GSSF supports the analysis of stand-alone GPS/SBAS systems as well as GPS/SBAS combined with Galileo • Example: Compare visibility and navigation system precision with and without SBAS support: EGNOS: INMARSAT 3 F2 (AOR-E) ESA ARTEMIS INMARSAT IOR-W (III-F5) QZSS & WAAS • UERE budgets drive NSPcalculation.
www.jaxa.jp www.nict.go.jp The Japanese Quasi-Zenith Satellite System • QZSS is to cover both Japan and Australia, • To maintain continuous visibility at high elevations (urban canyons) • Three satellites moving in different orbits but following the same relative track.
External Regional Integrity Service (ERIS) GSS Sites (Network of Stations) Station List: Site# Location Longitude [deg] Latitude [deg] 1 SEOUL 127.00 37.70 2 PUSAN 128.93 35.18 3 CHEJU 126.50 33.50
GSSF Raw Data GenerationExample • Effect of a clock jump, imposed as a Feared Event during the simulation on a Galileo Satellite observed at a Galileo Sensor station (Kourou). • The clock jump is defined by an additional bias of -0.0003 s applied at30 min after the simulation start time. Due to environmental delays on the signal and clock offsets Jump of 90 km
COOPERS(Co-operative Networks for Intelligent Road Safety) Integrated EU-Project with the following objectives: • Establish methodology for the integration of traffic control, traffic management and traffic information systems • Develop cost-efficient and advanced roadside and vehicle-side sensors and positioning-based situation-dependable driver assistance system (OBU) • Evaluate whether such methods will meet the overall target to improve safety • Assess what additional value can be achieved by Galileo for robust positioning, applying measurement campaigns and calibrated simulation using GSSF • Kick-off in February 2006 (40 partners, initially for 18 months with a possible extension towards 4 years, co-funded by the EU)
Simulation of Mobile Users • GSSF supports the simulationof mobile users: • Ground-based vehicles • Aircraft in flight • Satellites in LowEarth Orbit (LEO) • Errors such as clockfailures can be simulatedalong the trajectories.
Experiment (pwpSystems) • OBU Prototype Development • Sensory & • Positioning Algorithms • Measurement Campaigns • Optimise combination of sensory and algorithms • Evaluate potential for performance improvement applying Galileo Cooperation for Robust Positioning Simulation (VEGA) • Extensions to GSSF • Interface to or Integration of OBU Model • Validation & Calibration for Reference Measurements (GPS) • Simulation with Galileo GPS-Performance (ESOC) • Provision of up-to-date GPS Performance Data • Support to OBU Modelling (Algorithms) • Support for Validation & Calibration of Simulation
Summary & Main Strengths of GSSF • Rigorously validated against real data or trust-worthy simulated data • Specifically tailored towards the needs of the Galileo community • Is being maintained by VEGA on behalf of ESA • Can be further upgraded to match evolving requirements • Updates to SVS capability successfully completed recently(Inclusion of Galileo Integrity Concept) • Galileo performance assessment is currently ongoing on behalf ofESA and in preparation of Galileo CDR in June 2007. • RDG calibration with GIOVE-A data is ongoing. • Approx. 300 licenses have been granted up to now by ESA worldwide
www.gssf.info www.vega-group.com frank.zimmermann@vega.de Consulting and Technology Technical Excellence . Pragmatic Solutions . Proven Delivery