METIS First Master Training & Seminar Galileo/EGNOS and GPS & Augmented/Differential GPS Prepared by Mamadou Traore GEMCO email: mamadou_t@hotmail.com
European Navigation Satellites GALILEO It will achieve full independence through dedicated system under civil control EGNOS It provides an independently controlled civil complement to military GPS and GLONASS METIS First Master Training & Seminar, Ifrane (Morocco), 15-16.03.2007
GPS and GLONASS without augmentation GPS/GLONASS Satellites Like all other conventional systems, GPS and GLONASS are subject to errors that can degrade the precision of the systems. These are: Multipath Ionospheric Tropospheric Satellite clock Orbit Receiver and Noise - Selective availability, if any User calculates position Neither GPS nor GLONASS can provide Continuity, Availability, Integrity and Accuracy to be used as sole means of air navigation for all phases of flight. So, augmentation is needed to meet operational requirements METIS First Master Training & Seminar, Ifrane (Morocco), 15-16.03.2007
GPS and GLONASS Augmentation 2- Applies correction to GPS/GLONASS Satellites 1- User calculates Position 2- Applies correction to Calculated Position 1- Receiver calculates Position 4- Transmits error 2- Compares to its own Position 3- Calculates error METIS First Master Training & Seminar, Ifrane (Morocco), 15-16.03.2007
Benefits of Augmentation GPS/GLONASS augmentation systems meet the operational needs for all phases of flight by providing the four important requirements: Accuracy: how correct is the aircraft position estimate; thanks to differential corrections Integrity: the largest aircraft position error can reach without detection; thanks to monitoring algorithms Availability: how often can the aircraft use the systems and have the desired Accuracy and Integrity; GEOs can be used as additional ranging signals Continuity: the probability that an operation once commenced can be completed METIS First Master Training & Seminar, Ifrane (Morocco), 15-16.03.2007
Different Types of Augmentation DGPS (many transmitting beacons, ionos. influence) Aircraft-Based Augmentation System (ABAS) - RAIM (Receiver Autonomous Integrity Monitoring) - AAIM (Aircraft Autonomous Integrity Monitoring); INS + Altimetry aiding - FANS (Future Air Navigation System) (low cost, needs many visible satellites) Ground-Based Augmentation System (GBAS) Space-Based Augmentation System (SBAS) METIS First Master Training & Seminar, Ifrane (Morocco), 15-16.03.2007
Aircraft-Based Augmentation System ABAS achieves the 4 requirements of augmentation in the following processing schemes: - Integrity monitoring of the position solution - redundant information (Receiver Autonomous Integrity Monitoring) - additional onboard sensors (Aircraft Autonomous Integrity Monitoring) - Continuity Aiding: using information of alternative sources - Availability Aiding: for the position solution - Accuracy Aiding: through estimation of errors METIS First Master Training & Seminar, Ifrane (Morocco), 15-16.03.2007
Ground-Based Augmentation Types Local Area Augmentation Pseudo-Satellites (Pseudolites) Local Area Augmentation System (LAAS) Ground-Based Regional Augmentation System (GRAS) METIS First Master Training & Seminar, Ifrane (Morocco), 15-16.03.2007
Simple Pseudolite Concept GPS/GLONASS satellite A Pseudolite works as a complete “ground-based satellite. Pseudolite position is described in geographical terms while GPS/GLONASS are in the orbital elements used by satellites Satellite signal direct to user GPS User Satellite signal to Pseudolite Pseudolite makes the following: Measures the satellite signals Creates a precisely timed GPS-like signal Then transmits it over a data link to user Pseudolite at a known point METIS First Master Training & Seminar, Ifrane (Morocco), 15-16.03.2007
Simple Synchrolite Concept GPS/GLONASS satellites Synchrolite works as an “electronic mirror ”: Satellite signal direct to user Synchrolite user Satellite signals to Synchrolite Four reflected satellite signals Coherent replica of a satellite signal “reflected” by synchrolite and synchronized to a received satellite signal. A Synchrolite has much lesser latency than Pseudolite or any typical reference station Synchrolite at a known position METIS First Master Training & Seminar, Ifrane (Morocco), 15-16.03.2007
GPS/GLONASS augmentation through Pseudolite Availability: each additional Pseudolite ranging signal represents one less Satellite signal than required for basic navigation Continuity: since satellites and Pseudolites are separate systems which can be managed by different organizations, the probabililty of a common failure is small Accuracy: carefully located Pseudolites are available for aircraft in flight below the horizon. Therefore, this will improve the vertical guidance for aircraft Integrity: using additional ranging and satellite signals, Fault Detection and Fault Exclusion (FDE) can be done METIS First Master Training & Seminar, Ifrane (Morocco), 15-16.03.2007
Local Area Augmentation System LAAS is a ground-based system which intended to provide the 4 operational requirements in order satisfy aircraft needs for precision approach, landing and surface navigation in very poor visibility. With 20 NM range. The benefits of LAAS are multiple: Remote Coverage: can augment WAAS in locations with low cost Modified Approaches: to avoid Obstacles, Noises in sensitive area or crowed airspace Multiple runway coverage: one LAAS can serve an entire Airport Surface Navigation: can be used for ground navigation and taxiing METIS First Master Training & Seminar, Ifrane (Morocco), 15-16.03.2007
Ground-Based Regional Augmentation System GRAS is a ground-based system which will broadcast information through a well developed local VHF network. Used to enhance the safety and efficiency of aircraft operations in all phases of flight (en-route, terminal and instrument approach with vertical guidance). With 200 NM range. The benefits of GRAS are: Operational for all phases of flight: en-route, terminal and instrument approach with vertical guidance operations Deploy on Demand: a GRAS can be modified to provide service in specific area only METIS First Master Training & Seminar, Ifrane (Morocco), 15-16.03.2007
Different Types of SBAS European Geostationary Navigation Overlay Service (EGNOS) Wide Area Augmentation System (WAAS) MTSAT Satellite Augmentation Service (MSAS) GPS And Geo-Augmentation Navigation (GAGAN) Satellite Navigation Augmentation Service (SNAS) Military GPS Augmentation System (MGAS) METIS First Master Training & Seminar, Ifrane (Morocco), 15-16.03.2007
Space-Based Augmentation System Concept GPS/GLONASS Satellites GEO 4 Integrity & Ranging+ corrections Augmented Navigation Reference Stations 3 1 SBAS message Master Station 2 METIS First Master Training & Seminar, Ifrane (Morocco), 15-16.03.2007
EGNOS and Other Existing GNSS Systems METIS First Master Training & Seminar, Ifrane (Morocco), 15-16.03.2007
Difference between WAAS, EGNOS and MSAS All 3 Space-Based Augmentation Systems are compatible to each other; so, in principle, they are the same. The main difference between DGPS and SBAS is the calculation of the Total Electron Content (TEC) map for ionospheric corrections With DGPS, every single reference station, after comparing its own position with the calculated position, transmits this information on a certain band, as correction. For SBAS, this is different. Here, the monitoring stations do not provide single isolated corrections, but from all stations together a correction map for a wide area. So, every receiver corrects its position by using this data. That way, the accuracy is even better than with DGPS. METIS First Master Training & Seminar, Ifrane (Morocco), 15-16.03.2007
Highest Level of service supported Types of SBAS Services Types of SBAS Service Corrections Highest Level of service supported GNSS satellite and GEO ranging No correction Through NPA Basic differential corrections Clock and ephemeris Precise differential corrections Clock, ephemeris and ionosphere Through APV 2 METIS First Master Training & Seminar, Ifrane (Morocco), 15-16.03.2007
Level of service from GNSS augmentation elements Oceanic en-route Continental en-route Terminal Instrument Approach and Landing ABAS Suitable for navigation when fault detection and exclusion (FDE) is available Suitable for navigation when RAIM is usable Suitable for NPA when RAIM is available and another service is usable at alternate aerodrome SBAS Suitable for navigation Suitable for NPA and APV depending on SBAS performance GBAS N/A May be used as an input source for approved navigation systems Suitable for NPA and PA CAT1 (potentially CAT2 and CAT3) METIS First Master Training & Seminar, Ifrane (Morocco), 15-16.03.2007
GNSS avionics standards for augmentation Augmentation systems Technical Standard Order (TSO) Minimum Operational Performance Standards/Minimum Aviation Systems Performance Standards (MOPS/MASPS) ABAS TSO-C129 A Level 2 (en-route) TSO-C129 A Level 1-3 (NPA) RTCA / DO-208 EUROCAE ED – 72 A SBAS TSO-C145 A TSO- C 146 A RTCA / DO-229 C EUROCAE (under development) GBAS Under development RTCA / DO 245 RTCA / DO 246 B RTCA / DO 253 A EUROCAE ED - 95 METIS First Master Training & Seminar, Ifrane (Morocco), 15-16.03.2007
How can SBAS augment GPS/GLONASS GEO Differential Corrections Use/Don’t Use Message GPS-Like Signal + Accuracy + Availability + Continuity + Integrity METIS First Master Training & Seminar, Ifrane (Morocco), 15-16.03.2007
EGNOS GEO Satellites METIS First Master Training & Seminar, Ifrane (Morocco), 15-16.03.2007
EGNOS Architecture METIS First Master Training & Seminar, Ifrane (Morocco), 15-16.03.2007
EGNOS Extension Plan for MEDA METIS First Master Training & Seminar, Ifrane (Morocco), 15-16.03.2007
METIS First Master Training & Seminar, Ifrane (Morocco), 15-16.03.2007
MULTIMODAL MISSION REQUIREMENTS Civil Aviation: Primary means of navigation down to Precision Approach with vertical Accuracy of 7.7 meters Maritime: Specified to be better than 4 meters in European Coastal waters Expected performance around 1 meter horizontal accuracy Land Applications: Specified to be better than 4 meters in continental Europe (Ref: EGNOS Mission Requirement Document, v 1.2) METIS First Master Training & Seminar, Ifrane (Morocco), 15-16.03.2007
GNSS Performance Requirements METIS First Master Training & Seminar, Ifrane (Morocco), 15-16.03.2007
ICAO Classification of Approaches NPA Non Precision Approaches APV Approaches with Vertical Guidance PA Precision Approaches RNAV Lateral and vertical guidance Conventional systems Conventional systems RNAV Lateral guidance RNAV Lateral and vertical guidance APV. BaroV NAV APV I&II VOR/DME NDB Localizer ABAS DME/DME BaroVNAV ABAS DME/DME SBAS GNSS Galileo ILS MLS PAR GBAS METIS First Master Training & Seminar, Ifrane (Morocco), 15-16.03.2007
Services provided by EGNOS EGNOS system will provide the following services: GEO Ranging (R-GEO): Transmission of GPS-like signals from 3 GEO : AOR-E, IOR and ARTEMIS. This will augment the number of navigation satellites available to the users. GNSS Integrity Channel (GIC): Broadcasting of integrity information. This will increase the availability of GPS/GLONASS/EGNOS navigation service performance, mainly its accuracy, up to the NPA Wide Area Differential (WAD): Broadcasting of differential corrections. This will increase the GPS/GLONASS/EGNOS service performance, mainly its accuracy, up to the level of PA METIS First Master Training & Seminar, Ifrane (Morocco), 15-16.03.2007
EGNOS Performance for Civil Aviation Compliant for the En-Route Phases of Flight Global availability better than 99.999% (assuming GIC/RAIM combination) Compliant for the NPA Phase of Flight Global availability better than 99.998% (assuming GIC/RAIM combination) Provision of Precision Approach Objective: to achieve APV-2 (VAL=20m) (Global Availability of 99%) METIS First Master Training & Seminar, Ifrane (Morocco), 15-16.03.2007
EGNOS Safety of Life Service (SoL) Must stringent level of signal in space performance to all Communities of Safety of Life users over Europe Accessible to any user equipped with a GPS/SBAS compatible receiver Compliant with aviation APV-I intended to support applications in other SoL domains Should be declared available following appropriate certification process METIS First Master Training & Seminar, Ifrane (Morocco), 15-16.03.2007
EGNOS Service Implementation Roadmap Open Service Readiness Commercial Service Readiness Safety Service Readiness Actions 2004 2005 2006 2007 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 System Evolutions Deliver system Certify operations for SoL Commercial service upgrade Extend to Mediterranean Services Open Service Commercial Service Safety Of Life Service METIS First Master Training & Seminar, Ifrane (Morocco), 15-16.03.2007
GPS and GEO Augmented Navigation (GAGAN) Spearheaded by ISRO and Airport Authority of India Eight reference stations The control centre and satellite uplink centre are located in Bangalore Shall support NPA and Cat 1 landing Should be operational in 2006 METIS First Master Training & Seminar, Ifrane (Morocco), 15-16.03.2007
GALILEO Service Open Service Access - Free to air, Mass Market, Simple positioning - Commercial - Encrypted, High accuracy, Guaranteed service Safety of Life - Unencrypted, Integrity certified METIS First Master Training & Seminar, Ifrane (Morocco), 15-16.03.2007
GALILEO Service (continued) Search and Rescue - near real-time, precise Public Regulated - Encrypted, Integrity, Continuous availability METIS First Master Training & Seminar, Ifrane (Morocco), 15-16.03.2007
EU Council Conclusions The EGNOS programme should be placed under the control of the GALILEO Joint Undertaking Inclusion of EGNOS management as part of the future GALILEO concession to be assessed EGNOS should receive public funding from different sources EGNOS should be certified for safety of life use (eg aviation) as soon as possible Improvements should be made in order to meet evolving international standards EGNOS extensions should be pursued to share its operation with other regions (eg MEDA) METIS First Master Training & Seminar, Ifrane (Morocco), 15-16.03.2007
Thank You! http://www.aui.ma/GNSS/metis/ METIS First Master Training & Seminar, Ifrane (Morocco), 15-16.03.2007