Transcript Document 7632170

GUILDANCE MATERIAL ON GENERATION,
PROCESSING & SHARING OF ASTERIX
CATEGORY 21 ADS-B MESSAGES
Jointly Presented by Australia and Hong Kong, China
ADS-B SITF/11
April 2012
Civil Aviation Department
Hong Kong, China
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
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 for deployment 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
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
Version 0.23
(Incorporated
DO260
standard)
Civil Aviation Department
Hong Kong, China
August
2005
16th APANPIRG
adopted Version
0.23 as baselined
version for APAC
August
2008
Version 1.0
(incorporated
DO260A
standard)
May
2011
Version 2.1
(incorporated
DO260B
standard)
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
Choice of ASTERIX Version Number
• Most of the special DO260A and DO260B data items
cannot be reconstructed from a V0.23 data stream
V0.23
V2.1
(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
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
Asterix data from DO260A/B reports using some
techniques (e.g. generation of NUC value based on predefined table on combination of SIL, NIC and NAC)
• A more recent version of Cat 21 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
Specification of ASTERIX Message
Processing
• ASTERIX Cat 21 specification:
– Defines characteristics 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
Specification of ASTERIX Message
Processing
• ADS-B ground station specification:
– Defines the Asterix standard to 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
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
Specification of ASTERIX Message
Processing
• ANSPs that specify ADS-B ground
stations and ATM automation systems to
consider carefully what they need to
achieve
• Specification which simply require
compliance with a particular ASTERIX
standard will be inadequate in most
circumstances
Civil Aviation Department
Hong Kong, China
Specification of ASTERIX Message
Processing
• ANSPs together with suppliers should:
– Specify the Asterix standard version to be used
• Defines the message formats 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 received from the aircraft, the ground station is
required to fill appropriate optional Asterix data fields
– Specify the ATM automation system behaviour and
syntax checks applied to the Asterix data, including
any triggers for the system to discard data
Civil Aviation Department
Hong Kong, China
Generation of ASTERIX at
an ADS-B Ground Station
• Group 1 (Mandatory) – an Asterix Cat 21 message
should not be transmitted unless the mandatory data
items defined below are all present:
Data Items
Description
V0.23
V2.1
Remarks
X
Identifies source of data. Important
if validity checks are performed as
an anti spoofing capability
I021/010
Data Source
Identification
X
I021/030
Time of Day
X
I021/071 or Time of applicability of
I021/073
Position or Time of
Message reception for
position
Civil Aviation Department
Hong Kong, China
X
Data received with a Time of Day
too far in the past should be
discarded
Generation of ASTERIX at
an ADS-B Ground Station
Group 1 (Mandatory)
Data Items
Description
V0.23 V2.1
Remarks
I021/040
Target Report Descriptor
X
X
Indicates if report is a duplicate, on the
ground, is a simulated target, is a test
target. This needs to be checked by ATC
system prior to processing.
I021/080
Target Address
X
X
Included in all 1090ES downlink
messages, so always available. Used for
report/report linkage in ATC tracking.
I021/090
Figure of Merit/Quality
Indicators
X
X
Position cannot be used without quality
indicator
I021/130
Position in WGS-84 coordinates
X
X
Report cannot be used without position
Civil Aviation Department
Hong Kong, China
Generation of ASTERIX at
an ADS-B Ground Station
• Group 2 (Operationally Desirable) - should always be
transmitted whenever data are received by the ground
station from aircraft (if allowed by relevant Asterix
standard chosen):
Data Items
Description
I021/008
Aircraft operational
Status
I021/020
Emitter Category
I021/140
I021/145
V0.23 V2.1
Remarks
X
TCAS capability, Target state reporting
capability, CDTI capability, Single/dual
aircraft antenna
X
X
Aircraft or vehicle type
Geometric
Altitude/Height
X
X
Useful for RVSM monitoring
Flight Level
X
X
Flight level is an important information
to ATC
Civil Aviation Department
Hong Kong, China
Generation of ASTERIX at
an ADS-B Ground Station
Group 2 (Operationally Desirable)
Data Items
Description
V0.23 V2.1
Remarks
I021/155
Barometric Vertical
Rate
X
X
I021/157
Geometric Vertical
Rate
X
X
I021/160
Ground Vector
X
X
Provides excellent vector to support
extrapolation of positional data to time
of display
I021/170
Target Identification
X
X
This is the callsign/Flight ID is
extremely useful for ATC and matching
to the flight plan (if any)
I021/200
Target Status
X
X
This is the emergency type and is
highly desirable
Civil Aviation Department
Hong Kong, China
Used for predictive tools and safety
nets.
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 data from 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 be
transmitted should be configurable on item-by-item
basis depending on specific operational needs and link
bandwidth availability
Civil Aviation Department
Hong Kong, China
Processing of ASTERIX ADS-B
Data at ATC System
• An Asterix Cat 21 message should not be accepted by the
ATC System for processing unless it includes at least all
Group 1 data items
• The ATC system should process all received Asterix Cat
21 message data items that bring 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 operational needs
Civil Aviation Department
Hong Kong, China
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 are received 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
ADS-B Format Conversion
and Filter System
• Evolution of 1090ES ADS-B link
technology and 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
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
ANSP “A”
ADS-B Ground Station
Asterix CAT 21
Version “XA”
Ver “XA”
ATM Automation
System
Asterix CAT 21
Version “YA”
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”
ANSP “B”
Civil Aviation Department
Hong Kong, China
ATM Automation
System
Asterix CAT 21
Version “YB”
Ver “XB”
ADS-B Ground Station
Asterix CAT 21
Version “XB”
Domestic Data
Foreign Data
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 Cat 21 format to
ensure system interoperability 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
ATM automation 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
Thank you
Civil Aviation Department
Hong Kong, China