BLUEGNSS
Promoting EGNSS Operational Adoption in BLUEMED FAB

BLUEGNSS (Promoting EGNSS Operational Adoption in BLUEMED) was one of the H2020-Galileo-2015-1 projects selected for co-financing by GSA (the European GNSS Agency) in 2016. The project started in January 2016 and successfully achieved its objectives on June 2018.

The consortium, led by ENAV, was composed of the BLUE MED FAB ANSP Partners DCAC, HCAA, MATS and IDS (now IDS AirNav) as industrial Partner.

The primary objective of the BLUEGNSS Project was to harmonize the implementation of PBN approaches (RNP APCH - Required Navigation Performance Approach) among the BLUE MED FAB States by using EGNSS (European GNSS infrastructure such as EGNOS and upcoming Galileo). 

It is worth to mention that this was the first time in Europe that an operational implementation project was coordinated at FAB level. One of the advantages of such approach was that States/ANSPs that didn’t have enough experience in RNP APCH operational implementation received benefits from this intra-FAB cross fertilization.

The project was developed in 3 main streams:

• GNSS procedures design and validation
• GNSS training
• GNSS Monitoring

The project performed an extensive campaign of communication and result dissemination involving the main stakeholders (Airport authorities, Airspace Users, National Supervisory Authorities, Business Aviation Organizations, EUROCONTROL and ICAO) that took benefit from the related products.

GNSS procedures design and validation

The implementation of RNP APCH was envisaged by ICAO Assembly Resolution A37/11 urging States to implement approach procedures by 2016. The Assembly Resolution (not met by many European Countries), was superseded by EU regulation 2018/1048 laying down airspace usage requirements and operating procedures concerning performance-based navigation voted by Single Sky Committee on July 2018.On this regard BLUEGNSS paved the way to fulfil some of the obligations of the regulation for the BLUE MED Countries.

GNSS based procedures, known as RNP APCH, have been designed for 10 selected airports in order to increase their accessibility and safety taking the benefit of GNSS and related augmentation systems. For most of the concerned airports 3D approaches have been provided in replacement of less performing conventional approach procedures. Design has been done accordingly to all relevant ICAO documents (i.e. EUR Doc025, Doc8168, Doc9906, Doc9613). The flight inspection activities were performed by ENAV aircraft (Piaggio Avanti P-180) specifically equipped for RNP APCH validation.

The project enabled and speed up the signature of EGNOS Working Agreement with ESSP by MATS, HCAA and soon with DCAC.

Airports involved in the project were:

• Mitilini (LGMT), published in national AIP in 2019
• Ioannina (LGIO), published in national AIP in 2019
• Thessalonikki (LGTS), published in national AIP in 2019
• Kos (LGKO), published in national AIP in 2019
• Luqa (LMML), published in national AIP in 2018
• Cuneo (LIMZ), published in national AIP in 2018
• Parma (LIMP), published in national AIP in 2018
• Lamezia Terme (LICA), published in national AIP in 2018
• Bolzano (LIPB), experimental study
• Larnaca (LCLK), waiting for signature of  EGNOS Working Agreement with ESSP
• Paphos (LCPH), waiting for signature of EGNOS Working Agreement with ESSP

GNSS training

Specific training has been delivered to airspace procedure designers in order to let them able to deal with design of RNP APCH and related minima. Specific workshop were organized during project execution in order to share and discuss among design task leader and project members the design principles. This activity also represented a valid response to ICAO EANPG (European Air Navigation Planning Group - the governing body of ICAO in the EUR Region) findings and recommendations, in particular with reference to the identified scarcity of qualified personnel in the areas of PANS-OPS procedures design and oversight and the ensuing invitation to States to cooperate and share flight procedure design resources.

Further training has been delivered to ATCOs for the operational management of RNP APCH and to technical staff to let them know the principles of PBN and GNSS Monitoring.

GNSS Monitoring

The GNSS monitoring concept, as reported in the ICAO GNSS Manual, covers the following use cases:

1. GNSS performance assessment is a periodic off-line activity aimed at demonstrating the signal-in-space (SiS) conformance to ICAO Annex 10 relevant requirements (see Additional Resources).
2. GNSS operational status monitoring provides real-time information to technical staff and ATC services on the current operational status of GNSS services. RF interference (RFI) monitoring is typically part of this activity and monitors the GNSS spectrum providing timely warnings in case of potentially critical RFIs.
3. GNSS data recording is a legal recording service of GNSS data for post incident/accident investigations

In the framework of the BLUEGNSS project, the GNSS monitoring concept is a leading aspect that paved the way to the deployment of an innovative, multisource monitoring network able to:

• assess and record GNSS performance, measurements, and data; 
• analyze and report any detected RF interference (RFI) within the GNSS spectrum.

The BLUEGNSS monitoring network realized by IDS Airnav provides a common service of GPS, EGNOS, and Galileo performance assessment within the BLUE-MED area.

It has been realized through a TCP/IP star-network that connects some dedicated monitoring stations (developed by IDS Airnav and referred to as GNSS Operative Monitoring Equipment (GNOME)sentinels to a common collector, called CMF (Central Monitoring Facility). This unit is also fed by data coming from other external, already existing GNSS networks and services, i.e., EDAS, IGS/MGEX, EUREF, NavCen, and EGSC. This architectural choice is justified by the need to develop a flexible, scalable, and easily configurable network able to integrate and process data coming from several monitoring stations, even if they belong to independent networks. In this way, it is possible to increase the number of monitoring points within the BLUE-MED FAB without new installations. 

The GNOME sentinels are the key elements of the BLUEGNSS network. Simply speaking, such units are designed to receive positioning signals and process them in order to:

• check the integrity of GNSS signals (e.g., in terms of carrier-to-noise ratio, pseudorange errors, etc.) 
• produce statistical metrics able to characterize the GNSS performance in-situ (e.g., position accuracy, xDOP, number of used satellites, protection levels, etc.)
• monitor RF spectrum and detect possible intentional/unintentional interferences performed through SDR technology
• analyze the physical (PHY) and navigation (NAV) layers of positioning signals and record data and related metrics (according to relevant standards, see Additional Resources)
• investigate the cause of possible anomalies detected in-situ

The measurements acquired by each element of the network are gathered and processed by CMF. All computed KPIs are summarized within periodic reports (daily and monthly) that are automatically generated by the system and uploaded within the BLUE-MED portal for consulting by authorized personnel. 

The BLUEGNSS monitoring network has been successfully validated and now is fully operative. Indeed the activity of GNSS performance assessment is now on-going and statistically reports are periodically produced and uploaded on BLUE-MED website (www.bluemed.aero). 

Italian reports were used as Performance Assessment Reference by Italian CAA (ENAC). This important result permitted to approve GPS-based procedures without any additional mitigation (ENAC letter of 16th March 2018, nr. ENAC-VDG-16/03/2018-0028476-P).

Finally, the GNOME sentinels of Kos and Larnaca allowed to detect some interference events that were also confirmed by Pilot reports on GPS loss in Nicosia FIR during some days of March and April 2018. 

Dissemination

Project achievements have been extensively disseminated in public events such as World ATM Conference, Eurocontrol RAISG and NSG, BOV Aviation Outlook, ICAO Navigation System Panel, Aerosig.

Several papers have been developed for ICAO and an article has been written for Inside GNSS.

Project results is a fundamental milestone for BLUEMED and has a dedicated section into BLUEMED portal www.bluemed.aero.