GUILDANCE MATERIAL ON GENERATION, PROCESSING & SHARING OF ASTERIX CATEGORY 21 ADS-B MESSAGES

1. GUILDANCE MATERIAL ON GENERATION, PROCESSING & SHARING OF ASTERIX CATEGORY 21 ADS-B MESSAGES JointlyPresented by Australia and Hong Kong, China ADS-B SITF/11 April 2012 Civil Aviation Department Hong Kong, China

2. Introduction • “All Purpose Structured Eurocontrol Surveillance Information Exchange” (ASTERIX) Category 21 • A data format standard globally accepted by the Air Traffic Management (ATM) system manufacturing industry for sharing of ADS-B data with ATM automation systems • Used to convey ADS-B data from ADS-B ground stations to ATC processing and display system Civil Aviation Department Hong Kong, China

3. ASTERIX Cat 21 in Asia Pacific (APAC) Regions • During the 16th APANPIRG Meeting held in August 2005 • ASTERIX Category 21 version 0.23 which has incorporated DO260 standard was adopted as • the baselined ADS-B data format fordeployment of ADS-B ground stations • sharing of ADS-B data in the APAC Regions • DO260A and DO260B standards have yet been fully defined during that period Civil Aviation Department Hong Kong, China

4. Evolution of ASTERIX Cat 21 • Asterix standard has been developed over many years • Undergone continuous revisions to incorporate the latest ADS-B link technology November 2003 August 2005 August 2008 May 2011 16th APANPIRG adopted Version 0.23 as baselined version for APAC Version 2.1 (incorporated DO260B standard) Version 1.0 (incorporated DO260A standard) Version 0.23 (Incorporated DO260 standard) Civil Aviation Department Hong Kong, China

5. Choice of ASTERIX Version Number • Asia Pacific decided to use V0.23 as the version for sharing ADS-B data between States in 2005 • V0.23 • Provides adequate information for ATC operational services • Can be used with DO260, DO260A and DO260B ADS-B avionics/ground stations to provide ATC operational services • Cannot fully support all enhanced capabilities offered by DO260A and DO260B Civil Aviation Department Hong Kong, China

6. Choice of ASTERIX Version Number • Most of the special DO260A and DO260B data items cannot be reconstructed from a V0.23 data stream X (V2.1 as representation of ASTERIX CAT 21 Version after V0.23) • Nearly all V0.23 data items can be reconstructed from a received V2.1 data stream Civil Aviation Department Hong Kong, China

7. Support of DO260A/B using ASTERIX Cat 21 V0.23 • V0.23 does not directly support DO260A/B • Ground station software can generate useful V0.23 Asterixdata from DO260A/B reports using some techniques (e.g. generation of NUC valuebased on pre-definedtable on combination of SIL, NIC and NAC) • A more recent version of Cat21 is needed if there is a particular need for the ATC system to access to NIC/NAC or SIL or other data items that exist in DO260A/B • States are encouraged to review and determine additional DO260A/B fields beneficial to warrant adoption of newer versions of Asterix Cat 21 Civil Aviation Department Hong Kong, China

8. Specification of ASTERIX Message Processing • ASTERIX Cat 21 specification: • Definescharacteristics of data on the interface including items as optional and mandatory on the interface • It does NOT specify the behaviour of the transmitting ground station nor behaviour of the receiving ATM automation system Civil Aviation Department Hong Kong, China

9. Specification of ASTERIX Message Processing • ADS-B ground station specification: • Defines the Asterix standardto be adopted for outputting data and which optional Asterix data items are required to be delivered on the Asterix interface • indicates how the ground station processes and outputs every received DO260, DO260A and DO260B data element into an Asterix data element/field • indicates which and how each Asterix data element and field presented at the output are populated Civil Aviation Department Hong Kong, China

10. Specification of ASTERIX Message Processing • ATM automation system specification: • Defines which received Asterix data element and fields are processed and how they are processed • Defines which Asterix optional data fields are required by the ATM automation system Civil Aviation Department Hong Kong, China

11. Specification of ASTERIX Message Processing • ANSPs that specify ADS-B groundstations and ATM automation systems to consider carefully what they need toachieve • Specification which simply require compliance with a particular ASTERIX standard will beinadequate in most circumstances Civil Aviation Department Hong Kong, China

12. Specification of ASTERIX Message Processing • ANSPs together with suppliers should: • Specify the Asterix standard version to be used • Defines the messageformats that are placed on the link between ADS-B ground station and ATM automation systems • Specify the ADS-B ground station behaviour • When data is receivedfrom the aircraft, the ground station is required to fill appropriate optionalAsterix data fields • Specify the ATM automation system behaviourand syntax checks applied to the Asterix data, including any triggersfor the system to discard data Civil Aviation Department Hong Kong, China

13. Generation of ASTERIX at an ADS-B Ground Station • Group 1 (Mandatory) – an Asterix Cat21 message should not betransmitted unless the mandatory data items defined below are all present: Civil Aviation Department Hong Kong, China

14. Generation of ASTERIX at an ADS-B Ground Station Group 1 (Mandatory) Civil Aviation Department Hong Kong, China

15. Generation of ASTERIX at an ADS-B Ground Station • Group 2 (Operationally Desirable) - should always be transmitted wheneverdata are received by the ground station from aircraft (if allowed by relevant Asterixstandard chosen): Civil Aviation Department Hong Kong, China

16. Generation of ASTERIX at an ADS-B Ground Station Group 2 (Operationally Desirable) Civil Aviation Department Hong Kong, China

17. Generation of ASTERIX at an ADS-B Ground Station • Group 3 (Optional) – remaining data items belong to this Group which may need to be transmitted depending on availability of such datafrom aircraft and/or other specific operational needs • Specification for ADS-B ground station should take into account: • Transmission of all Group 1 (Mandatory) and Group 2 (Operationally Desirable) data items • Whether Group 3 (Optional) data items will betransmitted should be configurable on item-by-item basis depending on specific operational needs and link bandwidth availability Civil Aviation Department Hong Kong, China

18. Processing of ASTERIX ADS-B Data at ATC System • An Asterix Cat21 message should not be accepted by the ATC System for processingunless it includes at least all Group 1 data items • The ATC system should process all received Asterix Cat21 message data items thatbring operational benefits. The ATC System should appropriately process those Group 2 data items depending on operational need • Whether the ATC system will process Group 3 optional data items will depend on specific operationalneeds Civil Aviation Department Hong Kong, China

19. Data Sharing of ASTERIX ADS-B Data • Data items that should be included in data sharing: • Group 1 (Mandatory) • Group 2 (Operationally Desirable) when such data arereceived from aircraft • Subject to mutual agreement between the two data sharing parties concerned, Group 3 (Optional) data items needs to be shared Civil Aviation Department Hong Kong, China

20. ADS-B Format Conversion and Filter System • Evolution of 1090ES ADS-B link technologyand avionics standards will continue • Asterix standards will continue to evolve • ATC systems need to be adaptable and be able to cope with new functionality requirements and new message standards Civil Aviation Department Hong Kong, China

21. ADS-B Format Conversion and Filter System • Provides ADS-B format conversion between domestic and foreign ADS-B systems • Allows data meeting agreed sharing criteria to be passed through • Cost-effective way to provide the necessary protection and flexibility to adapt to new message standards Civil Aviation Department Hong Kong, China

22. ATM Automation System Asterix CAT 21 Version “YA” ADS-B Ground Station Asterix CAT 21 Version “XA” ANSP “A” Ver “XA” Ver “YA” • ADS-B Format Conversion & Filter System • Asterix Format Converter : Domestic: Ver XA/ Ver YA ; Foreign: Ver XA/ Ver YB • Pass only data that meet sharing criteria • Security features Agreed sharing format Ver “YB” Ver “YA” • ADS-B Format Conversion & Filter System • Asterix Format converter : Domestic: Ver XB/ Ver YB ; Foreign: Ver XB/ Ver YA • Pass only data that meet sharing criteria • Security features Ver “YB” Ver “XB” ATM Automation System Asterix CAT 21 Version “YB” ADS-B Ground Station Asterix CAT 21 Version “XB” ANSP “B” Domestic Data Foreign Data Civil Aviation Department Hong Kong, China

23. Conclusion • To recognize differences between DO-260, DO260A, DO260B for ADS-B ground stations and Asterix Cat 21 • To agree on proposed mandatory, desirable and optional ADS-B data fields for sharing of ADS-B data in Asterix Cat21 format to ensure systeminteroperability and harmonize ADS-B implementation in APAC Regions • To take note of possibility of deploying ADS-B format conversion & filter (ADS-B FC&F) system in overall design and integration of ATMautomation systems and ADS-B ground stations • To adopt this “Guidance Material on Generation, Processing and Sharing of Asterix Category 21 ADS-B Messages” for use by APAC States/Administrations Civil Aviation Department Hong Kong, China

24. Thank you Civil Aviation Department Hong Kong, China