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EGNOS Ionosphere R elated Activities S. Schlüter , R. Prieto- Cerdeira. SBAS IWG New Delhi 05-07/02/2014. Topics. EGNOS V2.x.x Ionosphere Related Activities EGEP Ionosphere Related Activities: EGNOS V3 EGEP Activities for the Characterization of the Ionosphere
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EGNOS Ionosphere Related ActivitiesS. Schlüter, R. Prieto-Cerdeira SBAS IWG New Delhi 05-07/02/2014
Topics • EGNOS V2.x.x Ionosphere Related Activities • EGEP Ionosphere Related Activities: • EGNOS V3 • EGEP Activities for the Characterization of the Ionosphere • Activities with African Countries and External Partners • Status/Way forward
EGNOS V2 IONO Objectives • Objectives of V2 Ionospheric Work Packages: • General focus of all activities is to improve availability in front of severe solar max ionosphericconditions • Minor changes/tuning related to some workarounds implemented in the past • V2.4.2 considers also major algorithmic changesin the CPF
EGEP/EGNOS V3 Ionosphere Related Activities • Main Objectives of EGEP/EGNOS V3 IONO Activities: • Improving of Means/Tools to support development EGNOS V3 (and V2 releases) • Improving/Consolidation of Means/Tools for the future qualification of EGNOS V3 • Improving of Means/Tools to support other SBAS activities, e.g. Africa • Means/Tools are: • Characterization of the ionosphere (Indicators of Ionosphere Activity, Specifications, …) • Reference Models for performance assessment and qualification • Data (particular focus on: Africa, scintillations)
The European GNSS Programmes Definition of an Indicator of Ionospheric Activity Along-Arc TEC Rate (AATR) indicatoras the hourly Root Mean Square (RMS) of “weighted” Along-Arc Vertical TEC Rate. Where Dt can be 30 or 60 seconds • Comments: • The RMS of all the AATRs (all the satellites) during 1 hour is computed for a given receiver, in order to mitigate spurious values of AATR. • With the squared mapping, we mitigate the effect worst VTEC computed at low elevation. Stations used for AATR RMS computation
Generation of Ionospheric Reference Scenarios CDF of AATR RMS (Different for 3 Geomagnetic Regions) Requirement 3D Iono Model Selection of periods and data AART RMS Reference Scenarios RDG
ScintillationPerformance Analysis Separate Receiver effects from System effects
EGEP ID 66: MONITOR II Core for future EGNOS Iono related activities Launch of activity: March 2014 Users Contributing Receivers & Product Data MONITOR II IONO Repository & Products Processing EGNOS V2 & V3 Projects Testbeds GALILEO Project CNES Others.. ASECNA Project Laboratories CNES DLR ICASES I & II Others…
MONITOR II Products • Examples: • Bitgrabber data to replay selected scintillation events • GNSS observations (Ranges and Scintillation) • TEC maps • Scintillation Occurrence maps • AATR RMS • Ad hoc generation of ionospheric reference scenarios • Upgrades of Iono Modelling (GISM, NeQuick)
MONITOR: Ionospheric Experimental Station Network Central Archiving and Processing Facility
Activities with African Countries and External Partners • ESA/CNES Activities with ASECNA • Collaborationwith SANSA SAGAIE network • Collaboration with additional partners TBD at next IONO SBAS meeting Air Traffic Control Agency ASECNA (Agency for Aerial Navigation Safety in Africa and Madagascar)
SAGAIE: Two Stations Architectures Architecture 1: Dakar, Lomé FLEXPAK6 Novatel Rx, GPS GLO GAL data Collection PolarXS Septentrio Receiver, GPS, GLO, GAL data collection and scintillations parameters Archive all raw data measurements, Rinex it, and send it to Toulouse Bitgraber : 2XUSRPN200 for RF signal recording Architecture 2: Douala, Ouagadougou, Ndjamena
CNES ASECNA External data flow FTP Server ESA/MONITOR Data Flow between ASECNA/SAGAIENetwork and MONITOR CPF Monitor CPF Data archiving CNES SAGAIE Stations Rinex 3 + ISMR data Stations raw Data High level iono Products ESA MONITOR Stations High Quality Multi-GNSS Receiver Network
DAIS • Data Assimilation Techniques for Ionospheric Reference Scenarios (DAIS) Aiming to generate improved EGNOS Ionospheric Reference Scenarios by combining spaceborne and ground-based GNSS observations. • Development of a method for combined reconstruction of the ionosphere (Ground & Space GNSS & Model) • Filling of data gaps, in particular in African low latitudes and over oceans. • Improved modelling of theCrest (profile, HmF2 and FoF2)
Status • On-going & Future Activities: • On-going activities to further improve and optimize GIVD/GIVErelated algorithms in EGNOS V2 releases • Preparation of EGNOS V3 Phase C/D (Refinement and consolidation of tools and specifications) • Further development of Models and Tools with a strong focus on scintillation effects • MoU for Collaboration of ASECNA, ESA and CNES to be signed in February • SANSA agreed to host 2 stations in Namibia (Implementation: Mid 2014) • Increase of cooperation with external partners for data exchange and coordinated actions in support of EGNOS-V3 and SBAS-Ionogroup.
SAGAIE MAIN FEATURES SAGAIE = STATIONS ASECNA GNSS for ANALYSE of the IONOSPHERE EQUATORIALE CNES and ASECNA have decided in 2012 to deploy a GNSS data collection network in Sub-Saharian area for ionosphere characterization Cooperation agreement signed between ASECNA and CNES in 2012 CNES in charge of: Overall management, engineering, equipment's procurement and sites deployment ASECNA in charge of: sites hosting, Telecom network, and stations operations CNES has contracted Thales for stations AIV and for sites deployment Five sites were selected: Dakar, Lomé, Douala, Ouagadougou and N’Djamena Dakar and Ouagadougou are actually operational (deployed in May/June 2013) Douala Lome and Ndjamena will be deployed in July 2013
Station at Ouagadougou Airport Choke Ring antenna Novatel Rx Switch Fuse Server for monitoring and control Control Tower
Correlation coefficient between the RMS of the post-fit residuals of a ionospheric model and other indices: Local Time (LT), AATR, DST, Ap and Solar Flux (SF). Associated to Solar terminator High latitude receivers are more affected by geomagnetic activity The study includes six different receivers (see map) during some tens of days with high ionospheric activity (all days with DST<-100nT are included). 23
Iono Scintillation, Effects on SBAS • In SBAS systems ionospheric scintillations shall be considered for their effects in the following: • System level: • Loss-of-lock (SNR) of GNSS satellites at system (RIMS) level • Increase number of cycle-slips at (RIMS) system level • Increased code-phase and carrier-phase noise at (RIMS) system level • User level: • Loss-of-lock of GEO or MEO • SBAS Data demodulation errors • Cycle-slips • Increased code-phase and carrier-phase noise (integrity to be protected?)