1. Sustainable Energy – Sustainable ATC Surveillance Workshop – Eurocontrol, Brussels, April 2010 Agenda Item Wind Turbine Interference – Possible Mitigations Jason Strong, Eng Mgr Surveillance Sensors NATS En-Route Ltd

2. 2 Sustainable Energy – Sustainable ATC Surveillance Workshop – Eurocontrol, Brussels, April 2010 Mitigation Options » Guidelines includes a variety of mitigation options which should be considered. » The choice and appropriateness of mitigation options varies from case to case, influenced by: » Surveillance technology employed » Cooperative / Non-Cooperative » Age & Capability » Capacity » Supportability » Air Traffic Density » Number of flights per Hour » Airspace Volume » Air Traffic Complexity » Mix of Aircraft » Military / State Aircraft » En-Route or Terminal Control

3. 3 Sustainable Energy – Sustainable ATC Surveillance Workshop – Eurocontrol, Brussels, April 2010 Mitigation Applicability » Guidelines Identifies different options for different Surveillance Classifications » Non-Cooperative Surveillance Sensor » Cooperative Surveillance Sensors » Operational » Wind Turbine » It is rare & unlikely that a single mitigation technique is sufficient on its own. Often a combination of options needs to be employed.

4. 4 Sustainable Energy – Sustainable ATC Surveillance Workshop – Eurocontrol, Brussels, April 2010 Risks identified requiring mitigation » Reduced PSR Probability of Detection (Pd) » PSR False Targets » PSR Positional Accuracy » Overload of PSR Capabilities (Capacity) » Reduced SSR Pd » SSR False Targets » SSR Position Accuracy » Guidelines identify which mitigations are effective at addressing each type of risk.

5. 5 Sustainable Energy – Sustainable ATC Surveillance Workshop – Eurocontrol, Brussels, April 2010 Mitigation Options Table 1 – Page 48

6. 6 Sustainable Energy – Sustainable ATC Surveillance Workshop – Eurocontrol, Brussels, April 2010 Mitigation Options Table 2 – Page 49

7. 7 Sustainable Energy – Sustainable ATC Surveillance Workshop – Eurocontrol, Brussels, April 2010 Non-Cooperative Surveillance Sensor » Blank Azimuth Sector » Suppress returns in a range / azimuth sector » Filtering of Wind Farm false returns » Strengthen Track Initiation Conditions » Adapt PSR overload prevention facilities » Upgrade PSR processing capabilities » Upgrade PSR output interface capabilities » In-Fill PSR » In-Fill MSPSR

8. 8 Sustainable Energy – Sustainable ATC Surveillance Workshop – Eurocontrol, Brussels, April 2010 PSR Blanking » Either a whole azimuth sector or range defined. » Effective way of addressing clutter & capacity related issues. » Obvious drawback of blanking out real aircraft returns » Maybe be suitable in certain operational situations, e.g.: » Low Risk of non-cooperative aircraft » Low complexity » Low traffic density

9. 9 Sustainable Energy – Sustainable ATC Surveillance Workshop – Eurocontrol, Brussels, April 2010 PSR Processing » Improved Processing Techniques » Increase Probability of Detection » Reduce the number of false plots » Improve the acquisition of targets through enhanced track initiation techniques » Use of Non-Auto Initiation zones » Several manufacturers looking at enhancements to existing technology or new/alternative replacement technology » Complex solution but potentially offers the most complete mitigation option.

10. 10 Sustainable Energy – Sustainable ATC Surveillance Workshop – Eurocontrol, Brussels, April 2010 Surveillance In Fill » Applicable to both cooperative & non cooperative surveillance » Places more emphasis mitigation at the end user rather than the Radar Head » Requires a surveillance picture to be built up from multiple surveillance sensors » Mosaic solution » Multi-Radar Tracking solution » Effective solution but limited in number of applications due to: » Computational limitations » Finite maximum number of surveillance sensors » Accuracy requirements

11. 11 Sustainable Energy – Sustainable ATC Surveillance Workshop – Eurocontrol, Brussels, April 2010 Cooperative Surveillance System » Blank SSR Transmission in an azimuth sector » In-Fill SSR » In-Fill Wide Area Multilateration (WAM) » In-Fill ADS-B » Improve SSR Anti-Reflection capability / Mode-S

12. 12 Sustainable Energy – Sustainable ATC Surveillance Workshop – Eurocontrol, Brussels, April 2010 Operational » Move ATC Route » Change airspace classification or create a Transponder Mandatory Zone

13. 13 Sustainable Energy – Sustainable ATC Surveillance Workshop – Eurocontrol, Brussels, April 2010 Wind Turbine » Move Turbines to outside Radar Line of Site » Move Turbines out of Critical Areas » Change Windfarm layout » Reduce number of turbines within Line of Site » Reduce Wind Turbine Reflectivity

14. 14 Sustainable Energy – Sustainable ATC Surveillance Workshop – Eurocontrol, Brussels, April 2010 Jason Strong Engineering Manager, Surveillance Sensors Jason.strong@nats.co.uk +44 1489 444701 NATS, Corporate & Technical Centre, 4000/4200 Parkway Whiteley, Fareham, Hampshire. UK PO15 7FL