EGNOS Ionosphere R elated Activities S. Schlüter , R. Prieto- Cerdeira

ESA UNCLASSIFIED – For Official Use

EGNOS Ionosphere Related ActivitiesS. Schlüter, R. Prieto-Cerdeira

SBAS IWG New Delhi 05-07/02/2014

ESA Presentation | 23/01/2013 | Slide 2


Topics

1. EGNOS V2.x.x Ionosphere Related Activities

2. EGEP Ionosphere Related Activities:1. EGNOS V32. EGEP Activities for the Characterization of the Ionosphere3. Activities with African Countries and External Partners

3. 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:

1. Improving of Means/Tools to support development EGNOS V3 (and V2 releases)

2. Improving/Consolidation of Means/Tools for the future qualification of EGNOS V3

3. 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)



24 April 2023 The European GNSS Programmes 6

Definition of an Indicator of Ionospheric Activity

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.

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

2( )STECAATR

M tD

D

onsa

Stations used for AATR RMS computation



Generation of Ionospheric Reference Scenarios

Requirement

AART RMS Selection of periods and data Reference

Scenarios

3D Iono Model

CDF of AATR RMS (Different for 3 Geomagnetic Regions)

RDG



Developed Scenarios



Scintillation Performance Analysis

Separate

Receiver effects

from

System effects



Scintillation Specifications (preliminary)



EGEP ID 66: MONITOR II

MONITOR IIIONO Repository &

ProductsProcessing

ContributingReceivers &

Product DataASECNA Project

Laboratories

CNES

DLR

ICASES I & II

Others…

EGNOS V2 & V3 Projects

Testbeds

GALILEO Project

CNES

Others..

UsersLaunch of activity: March 2014Core for future EGNOS Iono related activities



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

Air Traffic Control Agency ASECNA (Agency for Aerial Navigation Safety in Africa and Madagascar)

ESA/CNES Activities with ASECNA

Collaboration with SANSA Collaboration with additional partners

TBD at next IONO SBAS meeting

SAGAIE network



SAGAIE: Two Stations Architectures

NovAtel RxFlexPak6

splitter

INTERNET

Centre de contrôle(e-survey)

e-survey

Architecture 1: Dakar, Lomé

NovAtel FlexPak6 Rx

Septentrio PolarXs Rx

Bitgrabber RF GEMS

splitter

INTERNET

Centre de contrôle(e-survey)

GEAe-survey

Architecture 2: Douala, Ouagadougou, Ndjamena

Bitgraber : 2XUSRPN200 for RF signal recording

PolarXS Septentrio Receiver, GPS, GLO, GAL data collectionand scintillations parameters

Archive all raw data measurements,Rinex it, and send it to Toulouse

FLEXPAK6 Novatel Rx, GPS GLO GAL data Collection



Data Flow between ASECNA/SAGAIE Network and MONITOR CPF

Monitor CPFCNES SAGAIE

Stations

ESA MONITORStations

ASECNA

High Quality Multi-GNSSReceiver Network

Stations raw Data

FTPServer

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 theCrest (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.



Many Thanks for Your Attention!



SAGAIE MAIN FEATURES

1. 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

Novatel Rx

Switch

Fuse

Server for monitoring and control

Choke Ring antenna

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).

23

onsa

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 30 20

CAGL 37 26 74 -13 13 11

MAS1 27 47 72 -7 7 9

NKLG 0 52 69 -24 27 26

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).


GEO Roadmap – Satellite view

INM-3F2 EoL

ARTEMIS EoL

INM-4F2

ASTRA-4B

ASTRA-5B

INM-3F5 EoL

NIGCOMSAT-1R

V3 GEO

V2 TEST V2 OP

V2 TEST

2020

V2 OP

2017 2018 2019

V2 OP

V2 OP

2011 2012 2013 2014

V3 TEST

2016

V2 TEST EGEP (TBD)

V2 TEST / EGEP

V3 TEST

Africa Test Bed / OP (TBD) Africa OP

TBD

20212015

V2 TEST

V2 OP

V3 OP

V3 OP



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?)

Documents

EGNOS Ionosphere R elated Activities S. Schlüter , R. Prieto- Cerdeira