International Programmes & GNSS Monitoring Patrizio Vanni (patrizio.vanni@enav.it) GNSS expert ICAO PBN and PANS-OPS Provisions Implementation workshop Lisbon, 26 August 2015
Participation to PBN/GNSS Groups 2
ENAV expertize in PBN Procedure design (Algeria, Lebanon, Malesya) Flight inspection (Tunisia, Portugal, Croatia) Advanced PANS OPS Training (Marocco) Safety Assessment Helicopters regional network (RNP 0.3 and PiNs) GNSS Monitoring BLUEMED FAB PBN TF chairman 3
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Preamble At ICAO NSP#14 (November 2013) a working paper presented by Italy identified the need for further guidance on GNSS monitoring, including details on the objectives, acceptable methodology, policy for the retention of data, reporting and notification process in case of anomaly. A Drafting Group was established to start preparing guidance material on GNSS monitoring. Participants: USA UK Eurocontrol EC Canada Netherlands Russian Federation Italy ICCAIA Germany Japan Australia Spain 5
GMDG activities As first step, the GNSS Monitoring Drafting Group is preparing guidance material on GNSS core constellation performance assessment and legal recording and will propose amendments to relevant documentation. Activities: Definition of requirements for performance assessment and legal recording Definition of a common vocabulary and GNSS Monitoring concept Definition of Performance Assessment Methodology Identification of documentation impacted Since November 2013 several teleconferences have been held. Results have been presented at NSP#1 (April 2015). The documentation presented reached a good level of maturity. 6
States concerns Why GNSS Monitoring? What performance parameters need to be monitored for GPS and for the others constellations? and why? How to measure these parameters? Which density of stations is needed? What computation methodology? Which tools? How often performance reports are needed? Who should measure the parameters? States/NSAs, ANSPs, the core constellations service providers? International/regional organization? What to do if degradations/anomalies are measured? 7
Requirements identification Requirements extracted from Annex 10 vol.i Id Ref. Category Requirement GNSS-1 Att.D #12 Objectives Data recorded can be used periodically to confirm GNSS performance GNSS-2 Att.D #11.1 General All parameters available to users within a given service area should be recorded at representative locations in the service area GNSS-3 Att.D #11.2 General Recording system need not be independent GNSS-4 Att.D #11.2 Recording Recording System may be delegated to other States or entities GNSS-5 Att.D #11.2 Recording Data shall be logged continuously at 1Hz rate GNSS-6 Att.D #11.3 Recording Observed satellite carrier-to-noise density (C/N0) GNSS-7 Att.D #11.3 Recording Observed satellite raw pseudo-range code and carrier phase measurements GNSS-8 Att.D #11.3 Recording Broadcast satellite navigation messages, for all satellites in view GNSS-9 Att.D #11.3 Recording Relevant recording receiver status information GNSS-10 #2.1.4.2 Objectives State should monitor and record relevant GNSS data to support accident and incident investigations. GNSS-11 #2.1.4.2 Recording A State should ensure that GNSS data relevant to the operations required are recorded GNSS-12 #2.1.4.3 Recording Recordings should be retained for a period of at least fourteen days. When the recordings are pertinent to accident and incident investigations, they should be retained for longer periods until it is evident that they will no longer be required. GNSS-13 #2.1.4.3 Performance GNSS-6/7/8/9 support periodic confirmation of GNSS performance in the service area. [1] To be noted that this is a minimum requirement and that could be adjusted in order to be compliant with National Legislations for accident and incident investigations. 8
GNSS Monitoring Concept GNSS Monitoring GNSS Performance assessment GNSS Data recording GNSS Operational status monitoring GNSS Interference monitoring 9
Proposal definition GNSS performance assessment: is a periodic off-line activity performed by a State, or delegated entity, aiming to demonstrate SIS conformance vs. Annex 10 relevant requirements, it can be done at system and/or application level. GNSS operational status monitoring: is an activity performed by a State, or delegated entity, whose main objective is to provide information to technical staff and ATC services on the operational status of GNSS services in relation to a defined operation. GNSS Interference Monitoring: is a monitoring activity performed by a State, or delegated entity, whose main objective is to provide warning to technical staff and/or ATC services in case of detection of interferences on relevant GNSS band for a specific location. GNSS recording: is an activity performed by a State, or delegated entity, whose objective is to have GNSS status historical data to support postincident/accident investigations. It could cover also the legal recording part depending on national regulations. 10
Performance Assessment Process 11
Main outcomes [1/2] Integrity is the most critical parameter, due to its link to safety. It is applicable and measureable to the total system (including RAIM) and not to the core constellation itself. Different approaches for integrity are taken: For ABAS, integrity monitoring is done at airborne level with RAIM. Receivers that are certified in accordance with relevant international standards (e.g. MOPS, TSO series) have been designed to meet the integrity requirement defined in Table 3.7.2.4-1 of Annex 10 assuming GPS is compliant with key parameters defined in GPS SARPs Annex 10 and GPS SPS PS. For SBAS, integrity monitoring is done at ground segment level and the verification and assurance is given by the SBAS service provider. For GBAS a similar approach to SBAS is taken with responsibilities to local operators. For ABAS, it is suggested that States do not have to implement monitoring capabilities for integrity since integrity is provided in real time by RAIM. 12
Main outcomes [2/2] Availability, accuracy and continuity may have a different meanings (e.g. the meaning of continuity parameter for SIS performance requirements is different from the one defined for the SPS). Development of criteria (taking in account satellite geometry, tropospheric/ionospheric delay) for the determination of density of stations that can produce representative performance reports and can be used for data recording. Italy is assessing a criteria (so called 7 ) valid for mid latitudes. 13
Parameters proposal Performance Parameter Definition Targets Positioning Accuracy 95 percentile of the position error measured, intended as difference between 3.7.3.1.1.1 for GPS the estimated position by the receiver and the reference position, calculated 3.7.3.2.1.1 for GLONASS over an interval of 24hrs, for any point considered within the service volume. the targets reported referred to space/control segment only and does not take in account atmospheric or receiver errors. Range Domain Accuracy (Instantaneous URE) Difference between the pseudorange measured at a given location and the expected pseudorange as derived from the NAV message. 3.7.3.1.1.3 for GPS 3.7.3.2.1.3 for GLONASS The reported targets referred to space/control segment only and does not take into account atmospheric or receiver errors. Service Availability Probability of major service failure Continuity Probability of simultaneous major failures of 2 or more satellites Percentage of time over any 24hrs interval that the position accuracy is less than a specified value within the service volume. Probability that over a specific time interval, a healthy satellite s ranging signal error (excluding atmospheric and receiver errors) exceeds a specific range error limit. Continuity of service of a core constellation is the capability of the core 3.7.3.1.5 for GPS constellation to perform its function without unscheduled interruptions (e.g. 3.7.3.2.2 for GLONASS loss of availability, loss of PVT computation, etc) during the intended nominal operation. Probability of simultaneous failure (under the same conditions defined for major service failure) of 2 or more satellites. 3.7.3.1.2 for GPS 3.7.3.2.2 for GLONASS The targets do not take into account atmospheric or receiver errors. Up today only GPS targets exists as defined in 3.7.3.1.4. 1x10-9 14
Observations Error components assigned to Space and Control Segments (error budget components assigned to the User Segment such as the atmosphere, multipath, and receiver noise). For some parameters the target average location is used for stations disseminated globally so sometimes could be more useful to refer to the worst case target only, depending on the geographical extension of the area considered and number of stations used for the performance computation. 15
Approach proposed Today Use public reports provided by GNSS service providers or by other Organizations; Establish formal agreement with neighbouring State that is publishing performance reports and could cover the national interested area; Implement its own solutions in line with the guidelines provided in this document. 2020+ Core constellation service providers to provide global periodic performance reports towards relevant SPS parameters identified in Annex 10 vol.i. Reports can be used by States in combination or substitution of what already implemented. 16
Preliminary conclusions WHY? WHAT? HOW? WHO? IF? State Safety Oversight Function Ensure performances vs SARPS Significant core constellation parameters Network of stations (IGS, EDAS, etc) Off line activity State, International Organizations Core constellation service provider Share reports Escalate to International Organization 17
Next steps Inclusion of definitions in Annex 10 vol. I Guidelines to be included in Doc9849 GNSS Manual Real time monitoring concept Output from SESAR activities 18
RACOON: the ENAV Initiative Demonstration activity in the context of SJU Very Large Scale Demonstrations 2-year project (Fall 2014-Fall 2016) Demo on Milano Linate airport, including remote ATS service provision from Remote TWR Center located in Milano Malpensa Topics: Remote TWR for Single and Multiple Airports RNP APCH procedures GNSS approaches for helicopters GNSS Monitoring (including real time solutions) 19
RACOON: real time monitoring An IDS product customized for Tower ATCOs will be tested during RNP approaches demo campaign (dedicated training for ATCOs) Information provided to ATCOs based on data measured by a local GNSS station in Linate Main interface for ATCOs (green/red light): SBAS available/not available GPS available/not available Advanced info for technical staff: Service Availability, PDOP, Accuracy, Interference, etc 20
Conclusions Get confidence on GNSS based on measured data Harmonized regional cooperation is key topic Need to develop further the operational status monitoring concept Prepare to the challenging future for GNSS (new core constellations), are we ready for the introduction of Galileo? 21
patrizio.vanni@enav.it 22