EGNOS Ionosphere Related 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 Activities with African Countries and External Partners Status/Way forward

EGNOS V2 Release Road Map V2.2ext Qualified :June 2008 Certifiable release V2.3.1p Qualified: December 2011 Features: New RIMS (Alexandria, Athens, La Palma), NLES adaption to Inmarsat-4, Block IIF inclusion, Service coverage extension, migration to MPLS network technology, MT9/MT17 Coherency … V2.3.1i Qualified: July 2012 Features: Improved robustness to severe Iono activity ... 2.3.2 Qualified: August 2013 Features: New RIMS (Agadir, Abu Simbel), Optimisation of iono algorithms, Robustness against PRN 25 clock drift feared event (Bergen), Leap second anomaly correction (deployed in 2012) … V2.4.1M Qualified: ~July 2014 Features: Obsolescence resolution (CCF, NLES and EWAN), Qualification of ASTRA Sirius 5, New Missions (LPV-200, MOPS-D), Tuning of Iono processing … V.2.4.1P Qualified: ~ Mid 2015 (Procurement On-going) Features: Introduction of new ASTRA, 1 Step of Iono working activities, … V2.4.2 KO march 2014 Features: CPF obsolescence, RIMS A,B,C obsolescence, RIMS L2C capability, GEO ranging, 2 Step of Iono working activities

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 ionospheric conditions Minor changes/tuning related to some workarounds implemented in the past V2.4.2 considers also major algorithmic changes in 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)

Definition of an Indicator of Ionospheric Activity Along-Arc TEC Rate (AATR) indicator as 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 15 November, 2018 The European GNSS Programmes

Generation of Ionospheric Reference Scenarios CDF of AATR RMS (Different for 3 Geomagnetic Regions) Requirement 3D Iono Model AART RMS Selection of periods and data Reference Scenarios RDG

Developed Scenarios

Scintillation Performance Analysis Separate Receiver effects from System effects

Scintillation Specifications (preliminary)

Receivers & Product Data 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) VTEC map plot associated to VTEC-TOMION UPC external products (240 IGS stations) Latency : 1 < < 2 days

MONITOR: Ionospheric Experimental Station Network Central Archiving and Processing Facility

Activities with African Countries and External Partners ESA/CNES Activities with ASECNA Collaboration with 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

Data Flow between ASECNA/SAGAIE Network and MONITOR CPF CNES SAGAIE Stations ESA MONITOR ASECNA High Quality Multi-GNSS Receiver Network Stations raw Data FTP Server Data archiving CNES External data flow Rinex 3 + ISMR data High level iono Products ESA/MONITOR

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 the Crest (profile, HmF2 and FoF2)  

Status On-going & Future Activities: On-going activities to further improve and optimize GIVD/GIVE related 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-Iono group. (E.g. Boston College (LISN in South America, SCINDA and other initiatives in Africa), ASECNA (various locations in Africa), SANSA (South Africa), CHAIN (Canada), JRC-ISPRA (various locations).

Many Thanks for Your Attention!

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

Step 1 service area – for analysis during Phase B

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). RECEIVER LAT (Deg) Correlation (x 100) LT AATR DST Ap SF REYK 64 18 70 -25 30 27 ONSA 57 10 78 -33 35 13 POTS 55 11 83 -29 20 CAGL 37 26 74 -13 MAS1 47 72 -7 7 9 NKLG 52 69 -24 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

GEO Roadmap – Satellite view

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?)