Asterix category 021 - ADS-B Target Reports
category: 021
edition: 2.4
date: 2015-06-15
Preamble
Surveillance data exchange. ADS-B Target Reports.
Description of standard data items
I021/008 - Aircraft Operational Status
Definition: Identification of the operational services available in the aircraft while airborne.
Structure:
I021/008/RA - TCAS Resolution Advisory Active
1 bit [
.
]values:
0: TCAS II or ACAS RA not active
1: TCAS RA activeI021/008/TC - Target Trajectory Change Report Capability
2 bits [
..
]values:
0: No capability for Trajectory Change Reports
1: Support for TC+0 reports only
2: Support for multiple TC reports
3: ReservedI021/008/TS - Target State Report Capability
1 bit [
.
]values:
0: No capability to support Target State Reports
1: Capable of supporting target State ReportsI021/008/ARV - Air-Referenced Velocity Report Capability
1 bit [
.
]values:
0: No capability to generate ARV-reports
1: Capable of generate ARV-reportsI021/008/CDTIA - Cockpit Display of Traffic Information Airborne
1 bit [
.
]values:
0: CDTI not operational
1: CDTI operationalI021/008/NOTTCAS - TCAS System Status
1 bit [
.
]values:
0: TCAS operational
1: TCAS not operationalI021/008/SA - Single Antenna
1 bit [
.
]values:
0: Antenna Diversity
1: Single Antenna only
- Note:
-
- Additional Aircraft Status Information is available in the Reserved Expansion Field of Category 021.
I021/010 - Data Source Identification
Definition: Identification of the ADS-B station providing information.
Structure:
I021/010/SAC - System Area Code
- 8 bits [
........
]- raw value
I021/010/SIC - System Identification Code
- 8 bits [
........
]- raw value
- Note:
-
- The up-to-date list of SACs is published on the EUROCONTROL ASTERIX Web Site (http://www.eurocontrol.int/services/system-area-code-list).
I021/015 - Service Identification
Definition: Identification of the service provided to one or more users.
Structure:
- 8 bits [
........
] - raw value
Notes:
- The service identification is allocated by the system.
- The service identification is also available in item I023/015 [Ref. 3].
I021/016 - Service Management
Definition: Identification of services offered by a ground station (identified by a SIC code).
Structure:
- 8 bits [
........
] - unsigned quantity
- unit: “s”
- LSB = 1/2 s ≈ 0.50 s
Notes:
- This item contains the same information as item I023/101 in ASTERIX category 023 [Ref. 3]. Since not all service users receive category 023 data, this information has to be conveyed in category 021 as well.
- If this item is due to be sent according to the encoding rule above, it shall be sent with the next target report
I021/020 - Emitter Category
Definition: Characteristics of the originating ADS-B unit.
Structure:
8 bits [
........
]values:
0: No ADS-B Emitter Category Information
1: Light aircraft <= 15500 lbs
2: 15500 lbs < small aircraft <75000 lbs
3: 75000 lbs < medium a/c < 300000 lbs
4: High Vortex Large
5: 300000 lbs <= heavy aircraft
6: Highly manoeuvrable (5g acceleration capability) and high speed (>400 knots cruise)
7: Reserved
8: Reserved
9: Reserved
10: Rotocraft
11: Glider / sailplane
12: Lighter-than-air
13: Unmanned aerial vehicle
14: Space / transatmospheric vehicle
15: Ultralight / handglider / paraglider
16: Parachutist / skydiver
17: Reserved
18: Reserved
19: Reserved
20: Surface emergency vehicle
21: Surface service vehicle
22: Fixed ground or tethered obstruction
23: Cluster obstacle
24: Line obstacle
I021/040 - Target Report Descriptor
Definition: Type and characteristics of the data as transmitted by a system.
Structure:
Extended item.
I021/040/ATP - Address Type
3 bits [
...
]values:
0: 24-Bit ICAO address
1: Duplicate address
2: Surface vehicle address
3: Anonymous address
4: Reserved for future use
5: Reserved for future use
6: Reserved for future use
7: Reserved for future useI021/040/ARC - Altitude Reporting Capability
2 bits [
..
]values:
0: 25 ft
1: 100 ft
2: Unknown
3: InvalidI021/040/RC - Range Check
1 bit [
.
]values:
0: Default
1: Range Check passed, CPR Validation pendingI021/040/RAB - Report Type
1 bit [
.
]values:
0: Report from target transponder
1: Report from field monitor (fixed transponder)
(FX)
extension bit
0: End of data item
1: Extension into next extentI021/040/DCR - Differential Correction
1 bit [
.
]values:
0: No differential correction (ADS-B)
1: Differential correction (ADS-B)I021/040/GBS - Ground Bit Setting
1 bit [
.
]values:
0: Ground Bit not set
1: Ground Bit setI021/040/SIM - Simulated Target
1 bit [
.
]values:
0: Actual target report
1: Simulated target reportI021/040/TST - Test Target
1 bit [
.
]values:
0: Default
1: Test TargetI021/040/SAA - Selected Altitude Available
1 bit [
.
]values:
0: Equipment capable to provide Selected Altitude
1: Equipment not capable to provide Selected AltitudeI021/040/CL - Confidence Level
2 bits [
..
]values:
0: Report valid
1: Report suspect
2: No information
3: Reserved for future use
(FX)
extension bit
0: End of data item
1: Extension into next extentI021/040/(spare)
- 1 bit [
.
]I021/040/LLC - List Lookup Check
1 bit [
.
]values:
0: Default
1: List Lookup failed (see note)I021/040/IPC - Independent Position Check
1 bit [
.
]values:
0: Default (see note)
1: Independent Position Check failedI021/040/NOGO - No-go Bit Status
1 bit [
.
]values:
0: NOGO-bit not set
1: NOGO-bit setI021/040/CPR - Compact Position Reporting
1 bit [
.
]values:
0: CPR Validation correct
1: CPR Validation failedI021/040/LDPJ - Local Decoding Position Jump
1 bit [
.
]values:
0: LDPJ not detected
1: LDPJ detectedI021/040/RCF - Range Check
1 bit [
.
]values:
0: Default
1: Range Check failed
(FX)
extension bit
0: End of data item
1: Extension into next extent
Notes:
- Bit 3 indicates that the position reported by the target is within a credible range from the ground station. The range check is followed by the CPR validation to ensure that global and local position decoding both indicate valid position information. Bit 3=1 indicates that the range check was done, but the CPR validation is not yet completed. Once CPR validation is completed, Bit 3 will be reset to 0.
- The second extension signals the reasons for which the report has been indicated as suspect (indication Confidence Level (CL) in the first extension).
- Bit 2 indicates that the Range Check failed, i.e. the target is reported outside the credible range for the Ground Station. For operational users such a target will be suppressed. In services used for monitoring the Ground Station, the target will be transmitted with bit 2 indicating the fault condition.
- Bit 6, if set to 1, indicates that the position reported by the target was validated by an independent means and a discrepancy was detected. If no independent position check is implemented, the default value “0” is to be used.
- Bit 5 represents the setting of the GO/NOGO-bit as defined in item I023/100 of category 023 [Ref. 3].
- Bit 7, if set to 1, indicates that a lookup in a Black-list/White-list failed, indicating that the target may be suspect
I021/070 - Mode 3/A Code in Octal Representation
Definition: Mode-3/A code converted into octal representation.
Structure:
I021/070/(spare)
- 4 bits [
....
]I021/070/MODE3A - Mode-3/A Reply in Octal Representation
- 12 bits [
............
]- Octal string (3-bits per digit)
I021/071 - Time of Applicability for Position
Definition: Time of applicability of the reported position, in the form of elapsed time since last midnight, expressed as UTC.
Structure:
- 24 bits [
........................
] - unsigned quantity
- unit: “s”
- LSB = 1/27 s ≈ 7.81e − 3 s
Notes:
- The time of applicability value is reset to zero at every midnight.
- The time of applicability indicates the exact time at which the position transmitted in the target report is valid.
I021/072 - Time of Applicability for Velocity
Definition: Time of applicability (measurement) of the reported velocity, in the form of elapsed time since last midnight, expressed as UTC.
Structure:
- 24 bits [
........................
] - unsigned quantity
- unit: “s”
- LSB = 1/27 s ≈ 7.81e − 3 s
Notes:
- The time of the applicability value is reset to zero at every midnight.
- The time of applicability indicates the exact time at which the velocity information transmitted in the target report is valid.
- This item will not be available in some ADS-B technologies.
I021/073 - Time of Message Reception for Position
Definition: Time of reception of the latest position squitter in the Ground Station, in the form of elapsed time since last midnight, expressed as UTC.
Structure:
- 24 bits [
........................
] - unsigned quantity
- unit: “s”
- LSB = 1/27 s ≈ 7.81e − 3 s
- Note:
-
- The time of message reception value is reset to zero at every midnight.
I021/074 - Time of Message Reception of Position-High Precision
Definition: Time at which the latest ADS-B position information was received by the ground station, expressed as fraction of the second of the UTC Time.
Structure:
I021/074/FSI - Full Second Indication
2 bits [
..
]values:
3: Reserved
2: TOMRp whole seconds = (I021/073) Whole seconds - 1
1: TOMRp whole seconds = (I021/073) Whole seconds + 1
0: TOMRp whole seconds = (I021/073) Whole secondsI021/074/TOMRP - Fractional Part of the Time of Message Reception for Position in the Ground Station
- 30 bits [
..............................
]- unsigned quantity
- unit: “s”
- LSB = 1/230 s ≈ 9.31e − 10 s
I021/075 - Time of Message Reception for Velocity
Definition: Time of reception of the latest velocity squitter in the Ground Station, in the form of elapsed time since last midnight, expressed as UTC.
Structure:
- 24 bits [
........................
] - unsigned quantity
- unit: “s”
- LSB = 1/27 s ≈ 7.81e − 3 s
- Note:
-
- The time of message reception value is reset to zero at every midnight.
I021/076 - Time of Message Reception of Velocity-High Precision
Definition: Time at which the latest ADS-B velocity information was received by the ground station, expressed as fraction of the second of the UTC Time.
Structure:
I021/076/FSI - Full Second Indication
2 bits [
..
]values:
3: Reserved
2: TOMRp whole seconds = (I021/075) Whole seconds - 1
1: TOMRp whole seconds = (I021/075) Whole seconds + 1
0: TOMRp whole seconds = (I021/075) Whole secondsI021/076/TOMRP - Fractional Part of the Time of Message Reception for Position in the Ground Station
- 30 bits [
..............................
]- unsigned quantity
- unit: “s”
- LSB = 1/230 s ≈ 9.31e − 10 s
I021/077 - Time of ASTERIX Report Transmission
Definition: Time of the transmission of the ASTERIX category 021 report in the form of elapsed time since last midnight, expressed as UTC.
Structure:
- 24 bits [
........................
] - unsigned quantity
- unit: “s”
- LSB = 1/27 s ≈ 7.81e − 3 s
- Note:
-
- The time of ASTERIX report transmission value is reset to zero at every midnight.
I021/080 - Target Address
Definition: Target address (emitter identifier) assigned uniquely to each target.
Structure:
- 24 bits [
........................
] - raw value
I021/090 - Quality Indicators
Definition: ADS-B quality indicators transmitted by a/c according to MOPS version.
Structure:
Extended item.
I021/090/NUCRNACV - Navigation Uncertainty Category for Velocity NUCr or the Navigation Accuracy Category for Velocity NACv
- 3 bits [
...
]- raw value
I021/090/NUCPNIC - Navigation Uncertainty Category for Position NUCp or Navigation Integrity Category NIC
4 bits [
....
]raw value
- remark
- Notes:
- Apart from the “PIC” item, all items are defined as per the respective link technology protocol version (“MOPS version”, see I021/210).
- The primary subfield is kept for backwards compatibility reasons. Version 2 NIC-values shall be mapped accordingly. This is required to ensure that downstream systems, which are not capable of interpreting extensions 2 and 3 (because they use an ASTERIX
(FX)
extension bit
0: End of data item
1: Extension into next extentI021/090/NICBARO - Navigation Integrity Category for Barometric Altitude
- 1 bit [
.
]- raw value
I021/090/SIL - Surveillance (version 1) or Source (version 2) Integrity Level
- 2 bits [
..
]- raw value
I021/090/NACP - Navigation Accuracy Category for Position
- 4 bits [
....
]- raw value
(FX)
extension bit
0: End of data item
1: Extension into next extentI021/090/(spare)
- 2 bits [
..
]I021/090/SILS - SIL-Supplement
1 bit [
.
]values:
0: Measured per flight-hour
1: Measured per sampleI021/090/SDA - Horizontal Position System Design Assurance Level (as Defined in Version 2)
- 2 bits [
..
]- raw value
I021/090/GVA - Geometric Altitude Accuracy
- 2 bits [
..
]- raw value
(FX)
extension bit
0: End of data item
1: Extension into next extentI021/090/PIC - Position Integrity Category
- 4 bits [
....
]- raw value
I021/090/(spare)
- 3 bits [
...
]
(FX)
extension bit
0: End of data item
1: Extension into next extent
Notes:
- Apart from the “PIC” item, all items are defined as per the respective link technology protocol version (“MOPS version”, see I021/210).
- The primary subfield is kept for backwards compatibility reasons. Version 2 NIC-values shall be mapped accordingly. This is required to ensure that downstream systems, which are not capable of interpreting extensions 2 and 3 (because they use an ASTERIX edition earlier than 2.0) still get the required information
- “Version 1” or “Version 2” refers to the MOPS version as defined in data item I021/210, bits 6/4
- “Version 2” refers to the MOPS version as defined in data item I021/210, bits 6/4
- PIC=0 is defined for completeness only. In this case the third extension shall not be generated.
- For ED102A/DO260B PIC values of 7 and 9, the NIC supplements for airborne messages (NIC supplements A/B) and surface messages (NIC supplements A/C) are listed. For ED102A/DO260B PIC=8, the NIC supplements A/B for airborne messages are listed. For DO260A PIC values of 7 and 8, the NIC supplement for airborne messages is shown in brackets. The aircraft air-ground status, and hence message type (airborne or surface), is derived from the GBS-bit in I021/040, 1 st extension.
I021/110 - Trajectory Intent
Definition: Reports indicating the 4D intended trajectory of the aircraft.
Structure:
Compound item (FX)
I021/110/TIS - Trajectory Intent Status
Extended item.
I021/110/TIS/NAV
1 bit [
.
]values:
0: Trajectory Intent Data is available for this aircraft
1: Trajectory Intent Data is not available for this aircraftI021/110/TIS/NVB
1 bit [
.
]values:
0: Trajectory Intent Data is valid
1: Trajectory Intent Data is not validI021/110/TIS/(spare)
- 5 bits [
.....
]
(FX)
extension bit
0: End of data item
1: Extension into next extentI021/110/TID - Trajectory Intent Data
Repetitive item, repetition factor 8 bits.
I021/110/TID/TCA
1 bit [
.
]values:
0: TCP number available
1: TCP number not availableI021/110/TID/NC
1 bit [
.
]values:
0: TCP compliance
1: TCP non-complianceI021/110/TID/TCPN
Trajectory Change Point number
- 6 bits [
......
]- raw value
I021/110/TID/ALT - Altitude in Two’s Complement Form
- 16 bits [
................
]- signed quantity
- unit: “ft”
- LSB = 10 ft
- value > = − 1500 ft
- value < = 150000 ft
I021/110/TID/LAT - In WGS.84 in Two’s Complement
- 24 bits [
........................
]- signed quantity
- unit: “°”
- LSB = 180/223 ° ≈ 2.15e − 5 °
- value > = − 90 °
- value < = 90 °
I021/110/TID/LON - In WGS.84 in Two’s Complement
- 24 bits [
........................
]- signed quantity
- unit: “°”
- LSB = 180/223 ° ≈ 2.15e − 5 °
- value > = − 180 °
- value < 180 °
I021/110/TID/PT - Point Type
4 bits [
....
]values:
0: Unknown
1: Fly by waypoint (LT)
2: Fly over waypoint (LT)
3: Hold pattern (LT)
4: Procedure hold (LT)
5: Procedure turn (LT)
6: RF leg (LT)
7: Top of climb (VT)
8: Top of descent (VT)
9: Start of level (VT)
10: Cross-over altitude (VT)
11: Transition altitude (VT)I021/110/TID/TD
2 bits [
..
]values:
0: N/A
1: Turn right
2: Turn left
3: No turnI021/110/TID/TRA
Turn Radius Availability
1 bit [
.
]values:
0: TTR not available
1: TTR availableI021/110/TID/TOA
1 bit [
.
]values:
0: TOV available
1: TOV not availableI021/110/TID/TOV - Time Over Point
- 24 bits [
........................
]- unsigned quantity
- unit: “s”
- LSB = 1 s
I021/110/TID/TTR - TCP Turn Radius
- 16 bits [
................
]- unsigned quantity
- unit: “NM”
- LSB = 1/100 NM ≈ 1.00e − 2 NM
- value > = 0 NM
- value < = 13107/20 NM
Notes:
- NC is set to one when the aircraft will not fly the path described by the TCP data.
- TCP numbers start from zero.
- LT = Lateral Type
- VT = Vertical Type
- TOV gives the estimated time before reaching the point. It is defined as the absolute time from midnight.
- TOV is meaningful only if TOA is set to 1.
I021/130 - Position in WGS-84 Co-ordinates
Definition: Position in WGS-84 Co-ordinates.
Structure:
I021/130/LAT - Latitude
- 24 bits [
........................
]- signed quantity
- unit: “°”
- LSB = 180/223 ° ≈ 2.15e − 5 °
- value > = − 90 °
- value < = 90 °
I021/130/LON - Longitude
- 24 bits [
........................
]- signed quantity
- unit: “°”
- LSB = 180/223 ° ≈ 2.15e − 5 °
- value > = − 180 °
- value < 180 °
Notes:
- Positive longitude indicates East. Positive latitude indicates North.
I021/131 - High-Resolution Position in WGS-84 Co-ordinates
Definition: Position in WGS-84 Co-ordinates in high resolution.
Structure:
I021/131/LAT - Latitude
- 32 bits [
................................
]- signed quantity
- unit: “°”
- LSB = 180/230 ° ≈ 1.68e − 7 °
- value > = − 90 °
- value < = 90 °
I021/131/LON - Longitude
- 32 bits [
................................
]- signed quantity
- unit: “°”
- LSB = 180/230 ° ≈ 1.68e − 7 °
- value > = − 180 °
- value < 180 °
Notes:
- Positive longitude indicates East. Positive latitude indicates North.
I021/132 - Message Amplitude
Definition: Amplitude, in dBm, of ADS-B messages received by the ground station, coded in two’s complement.
Structure:
- 8 bits [
........
] - signed quantity
- unit: “dBm”
- LSB = 1 dBm
- Note:
-
- The value gives the amplitude of the latest received squitter.
I021/140 - Geometric Height
Definition: Minimum height from a plane tangent to the earth’s ellipsoid, defined by WGS-84, in two’s complement form.
Structure:
- 16 bits [
................
] - signed quantity
- unit: “ft”
- LSB = 25/22 ft ≈ 6.25 ft
- value > = − 1500 ft
- value < 150000 ft
- Note:
-
- LSB is required to be less than 10 ft by ICAO.
- A value of ‘0111111111111111’ indicates that the aircraft transmits a “greater than” indication.
I021/145 - Flight Level
Definition: Flight Level from barometric measurements,not QNH corrected, in two’s complement form.
Structure:
- 16 bits [
................
] - signed quantity
- unit: “FL”
- LSB = 1/22 FL ≈ 0.25 FL
- value > = − 15 FL
- value < 1500 FL
I021/146 - Selected Altitude
Definition: The Selected Altitude as provided by the avionics and corresponding either to the MCP/FCU Selected Altitude (the ATC cleared altitude entered by the flight crew into the avionics) or to the FMS Selected Altitude.
Structure:
I021/146/SAS - Source Availability
1 bit [
.
]values:
0: No source information provided
1: Source Information providedI021/146/S - Source
2 bits [
..
]values:
0: Unknown
1: Aircraft Altitude (Holding Altitude)
2: MCP/FCU Selected Altitude
3: FMS Selected AltitudeI021/146/ALT - Altitude
- 13 bits [
.............
]- signed quantity
- unit: “ft”
- LSB = 25 ft
- value > = − 1300 ft
- value < 100000 ft
Notes:
- The Selected Altitude provided in this field is not necessarily the “Target Altitude” as defined by ICAO.
- The value of “Source” (bits 15/14) indicating “unknown” or “Aircraft Altitude” is kept for backward compatibility as these indications are not provided by “version 2” systems as defined by data item I021/210, bits 6/4.
- Vertical mode indications supporting the determination of the nature of the Selected Altitude are provided in the Reserved Expansion Field in the subfield NAV.
I021/148 - Final State Selected Altitude
Definition: The vertical intent value that corresponds with the ATC cleared altitude, as derived from the Altitude Control Panel (MCP/FCU).
Structure:
I021/148/MV - Manage Vertical Mode
1 bit [
.
]values:
0: Not active or unknown
1: ActiveI021/148/AH - Altitude Hold Mode
1 bit [
.
]values:
0: Not active or unknown
1: ActiveI021/148/AM - Approach Mode
1 bit [
.
]values:
0: Not active or unknown
1: ActiveI021/148/ALT - Altitude
- 13 bits [
.............
]- signed quantity
- unit: “ft”
- LSB = 25 ft
- value > = − 1300 ft
- value < 100000 ft
Notes:
- This item is kept for backward compatibility but shall not be used for “version 2” ADS-B systems (as defined by data item I021/210, bits 6/4) for which item 146 will be used to forward the MCP/FCU or the FMS selected altitude information. For “version 2” ADS-B systems, the vertical mode indications will be provided through the Reserved Expansion Field in the subfield NAV .
I021/150 - Air Speed
Definition: Calculated Air Speed (Element of Air Vector).
Structure:
I021/150/IM
1 bit [
.
]values:
0: Air Speed = IAS, LSB (Bit-1) = 2 -14 NM/s
1: Air Speed = Mach, LSB (Bit-1) = 0.001I021/150/AS - Air Speed (IAS or Mach)
- 15 bits [
...............
]- Depends on the value of
150/IM
.
- In case of
150/IM == 0
:
- unsigned quantity
- unit: “NM/s”
- LSB = 1/214 NM/s ≈ 6.10e − 5 NM/s
- In case of
150/IM == 1
:
- unsigned quantity
- unit: “Mach”
- LSB = 1/1000 Mach ≈ 1.00e − 3 Mach
- Default:
- raw value
I021/151 - True Airspeed
Definition: True Air Speed.
Structure:
I021/151/RE - Range Exceeded Indicator
1 bit [
.
]values:
0: Value in defined range
1: Value exceeds defined rangeI021/151/TAS - True Air Speed
- 15 bits [
...............
]- unsigned quantity
- unit: “kt”
- LSB = 1 kt
Notes:
- The RE-Bit, if set, indicates that the value to be transmitted is beyond the range defined for this specific data item and the applied technology. In this case the True Air Speed contains the maximum value that can be downloaded from the aircraft avionics and the RE-bit indicates that the actual value is greater than the value contained in the field.
I021/152 - Magnetic Heading
Definition: Magnetic Heading (Element of Air Vector).
Structure:
- 16 bits [
................
] - unsigned quantity
- unit: “°”
- LSB = 360/216 ° ≈ 5.49e − 3 °
Notes:
- True North Heading is defined in the Reserved Expansion Field in the subfield TNH.
I021/155 - Barometric Vertical Rate
Definition: Barometric Vertical Rate, in two’s complement form.
Structure:
I021/155/RE - Range Exceeded Indicator
1 bit [
.
]values:
0: Value in defined range
1: Value exceeds defined rangeI021/155/BVR - Barometric Vertical Rate
- 15 bits [
...............
]- signed quantity
- unit: “ft/min”
- LSB = 25/22 ft/min ≈ 6.25 ft/min
Notes:
- The RE-Bit, if set, indicates that the value to be transmitted is beyond the range defined for this specific data item and the applied technology. In this case the Barometric Vertical Rate contains the maximum value that can be downloaded from the aircraft avionics and the RE-bit indicates that the actual value is greater than the value contained in the field.
I021/157 - Geometric Vertical Rate
Definition: Geometric Vertical Rate, in two’s complement form, with reference to WGS-84.
Structure:
I021/157/RE - Range Exceeded Indicator
1 bit [
.
]values:
0: Value in defined range
1: Value exceeds defined rangeI021/157/GVR - Geometric Vertical Rate
- 15 bits [
...............
]- signed quantity
- unit: “ft/min”
- LSB = 25/22 ft/min ≈ 6.25 ft/min
Notes:
- The RE-Bit, if set, indicates that the value to be transmitted is beyond the range defined for this specific data item and the applied technology. In this case the Geometric Vertical Rate contains the maximum value that can be downloaded from the aircraft avionics and the RE-bit indicates that the actual value is greater than the value contained in the field.
I021/160 - Airborne Ground Vector
Definition: Ground Speed and Track Angle elements of Airborne Ground Vector.
Structure:
I021/160/RE - Range Exceeded Indicator
1 bit [
.
]values:
0: Value in defined range
1: Value exceeds defined rangeI021/160/GS - Ground Speed Referenced to WGS-84
- 15 bits [
...............
]- unsigned quantity
- unit: “NM/s”
- LSB = 1/214 NM/s ≈ 6.10e − 5 NM/s
- value > = 0 NM/s
- value < 2 NM/s
I021/160/TA - Track Angle Clockwise Reference to True North
- 16 bits [
................
]- unsigned quantity
- unit: “°”
- LSB = 360/216 ° ≈ 5.49e − 3 °
Notes:
- The RE-Bit, if set, indicates that the value to be transmitted is beyond the range defined for this specific data item and the applied technology. In this case the Ground Speed contains the maximum value that can be downloaded from the aircraft avionics and the RE-bit indicates that the actual value is greater than the value contained in the field.
- The Surface Ground Vector format is defined in the Reserved Expansion Field in the subfield SGV.
I021/161 - Track Number
Definition: An integer value representing a unique reference to a track record within a particular track file.
Structure:
I021/161/(spare)
- 4 bits [
....
]I021/161/TRNUM - Track Number
- 12 bits [
............
]- raw value
I021/165 - Track Angle Rate
Definition: Rate of Turn, in two’s complement form.
Structure:
I021/165/(spare)
- 6 bits [
......
]I021/165/TAR - Track Angle Rate
- 10 bits [
..........
]- signed quantity
- unit: “°/s”
- LSB = 1/25 °/s ≈ 3.12e − 2 °/s
- value > = − 16 °/s
- value < = 16 °/s
Notes:
- A positive value represents a right turn, whereas a negative value represents a left turn.
- Maximum value means Maximum value or above.
- This item will not be transmitted for the technology 1090 MHz Extended Squitter.
I021/170 - Target Identification
Definition: Target (aircraft or vehicle) identification in 8 characters, as reported by the target.
Structure:
- 48 bits [
... 48 bits ...
] - ICAO string (6-bits per character)
I021/200 - Target Status
Definition: Status of the target
Structure:
I021/200/ICF - Intent Change Flag (see Note)
1 bit [
.
]values:
0: No intent change active
1: Intent change flag raisedI021/200/LNAV - LNAV Mode
1 bit [
.
]values:
0: LNAV Mode engaged
1: LNAV Mode not engagedI021/200/ME - Military Emergency
1 bit [
.
]values:
0: No military emergency
1: Military emergencyI021/200/PS - Priority Status
3 bits [
...
]values:
0: No emergency / not reported
1: General emergency
2: Lifeguard / medical emergency
3: Minimum fuel
4: No communications
5: Unlawful interference
6: DOWNED AircraftI021/200/SS - Surveillance Status
2 bits [
..
]values:
0: No condition reported
1: Permanent Alert (Emergency condition)
2: Temporary Alert (change in Mode 3/A Code other than emergency)
3: SPI set
Notes:
- Bit-8 (ICF), when set to “1” indicates that new information is available in the Mode S GICB registers 40, 41 or 42.
I021/210 - MOPS Version
Definition: Identification of the MOPS version used by a/c to supply ADS-B information.
Structure:
I021/210/(spare)
- 1 bit [
.
]I021/210/VNS - Version Not Supported
1 bit [
.
]values:
0: The MOPS Version is supported by the GS
1: The MOPS Version is not supported by the GSI021/210/VN - Version Number
3 bits [
...
]values:
0: ED102/DO-260 [Ref. 8]
1: DO-260A [Ref. 9]
2: ED102A/DO-260B [Ref. 11]I021/210/LTT - Link Technology Type
3 bits [
...
]values:
0: Other
1: UAT
2: 1090 ES
3: VDL 4
4: Not assigned
5: Not assigned
6: Not assigned
7: Not assigned
Notes:
- VN sub-field shall contain a value describing the MOPS used by each aircraft. The versions of other link technologies are assumed to be in line with the 1090 ES MOPS versions and the corresponding MASPS versions.
- Bit 7 (VNS) when set to 1 indicates that the aircraft transmits a MOPS Version indication that is not supported by the Ground Station. However, since MOPS versions are supposed to be backwards compatible, the GS has attempted to interpret the message and achieved a credible result. The fact that the MOPS version received is not supported by the GS is submitted as additional information to subsequent processing systems.
I021/220 - Met Information
Definition: Meteorological information.
Structure:
Compound item (FX)
I021/220/WS - Wind Speed
- 16 bits [
................
]- unsigned quantity
- unit: “kt”
- LSB = 1 kt
- value > = 0 kt
- value < = 300 kt
I021/220/WD - Wind Direction
- 16 bits [
................
]- unsigned quantity
- unit: “°”
- LSB = 1 °
- value > = 1 °
- value < = 360 °
I021/220/TMP - Temperature
- 16 bits [
................
]- signed quantity
- unit: “°C”
- LSB = 1/22 °C ≈ 0.25 °C
- value > = − 100 °C
- value < = 100 °C
I021/220/TRB - Turbulence
- 8 bits [
........
]- unsigned integer
- value > = 0
- value < = 15
I021/230 - Roll Angle
Definition: The roll angle, in two’s complement form, of an aircraft executing a turn.
Structure:
- 16 bits [
................
] - signed quantity
- unit: “°”
- LSB = 1/100 ° ≈ 1.00e − 2 °
- value > = − 180 °
- value < = 180 °
Notes:
- Negative Value indicates “Left Wing Down”.
- Resolution provided by the technology “1090 MHz Extended Squitter” is 1 degree.
I021/250 - Mode S MB Data
Definition: Mode S Comm B data as extracted from the aircraft transponder.
Structure:
Repetitive item, repetition factor 8 bits.
- 64 bits [
... 64 bits ...
]- BDS register with address
Notes:
- For the transmission of BDS20, item 170 should be used.
- For the transmission of BDS30, item 260 is used.
I021/260 - ACAS Resolution Advisory Report
Definition: Currently active Resolution Advisory (RA), if any, generated by the ACAS associated with the transponder transmitting the RA message and threat identity data.
Structure:
I021/260/TYP - Message Type (= 28 for 1090 ES, Version 2)
- 5 bits [
.....
]- raw value
I021/260/STYP - Message Sub-type (= 2 for 1090 ES, Version 2)
- 3 bits [
...
]- raw value
I021/260/ARA - Active Resolution Advisories
- 14 bits [
..............
]- raw value
I021/260/RAC - RAC (RA Complement) Record
- 4 bits [
....
]- raw value
I021/260/RAT - RA Terminated
- 1 bit [
.
]- raw value
I021/260/MTE - Multiple Threat Encounter
- 1 bit [
.
]- raw value
I021/260/TTI - Threat Type Indicator
- 2 bits [
..
]- raw value
I021/260/TID - Threat Identity Data
- 26 bits [
..........................
]- raw value
Notes:
- Version denotes the MOPS version as defined in I021/210, bits 6/4
- This data items copies the value of BDS register 6,1 for message type 28, subtype 2
- The “TYP” and “STYP” items are implementation (i.e. link technology) dependent.
- Refer to ICAO Annex 10 SARPs for detailed explanations [Ref. 10]
I021/271 - Surface Capabilities and Characteristics
Definition: Operational capabilities of the aircraft while on the ground.
Structure:
Extended item.
I021/271/(spare)
- 2 bits [
..
]I021/271/POA - Position Offset Applied
1 bit [
.
]values:
0: Position transmitted is not ADS-B position reference point
1: Position transmitted is the ADS-B position reference pointI021/271/CDTIS - Cockpit Display of Traffic Information Surface
1 bit [
.
]values:
0: CDTI not operational
1: CDTI operationalI021/271/B2LOW - Class B2 Transmit Power Less Than 70 Watts
1 bit [
.
]values:
0: >= 70 Watts
1: < 70 WattsI021/271/RAS - Receiving ATC Services
1 bit [
.
]values:
0: Aircraft not receiving ATC-services
1: Aircraft receiving ATC servicesI021/271/IDENT - Setting of IDENT Switch
1 bit [
.
]values:
0: IDENT switch not active
1: IDENT switch active
(FX)
extension bit
0: End of data item
1: Extension into next extentI021/271/LW - Length and Width of the Aircraft
- 4 bits [
....
]- raw value
I021/271/(spare)
- 3 bits [
...
]
(FX)
extension bit
0: End of data item
1: Extension into next extent
Notes:
- Version 2 (as defined in I021/210, bits 6/4) data technology protocols encode “No Data or Unknown” with value 0. In this case data item I021/271, first extension is not generated.
- As of edition 2.2 the structure of this data item has been changed. Edition 2.2 is not backwards compatible with previous editions.
I021/295 - Data Ages
Definition: Ages of the data provided.
Structure:
Compound item (FX)
I021/295/AOS - Aircraft Operational Status Age
Age of the information transmitted in item I021/008.
- 8 bits [
........
]- unsigned quantity
- unit: “s”
- LSB = 1/10 s ≈ 0.10 s
- value < = 51/2 s
I021/295/TRD - Target Report Descriptor Age
Age of the Target Report Descriptor, item I021/040
- 8 bits [
........
]- unsigned quantity
- unit: “s”
- LSB = 1/10 s ≈ 0.10 s
- value < = 51/2 s
I021/295/M3A - Mode 3/A Age
Age of the Mode 3/A Code, item I021/070
- 8 bits [
........
]- unsigned quantity
- unit: “s”
- LSB = 1/10 s ≈ 0.10 s
- value < = 51/2 s
I021/295/QI - Quality Indicators Age
Age of the Quality Indicators, item I021/090
- 8 bits [
........
]- unsigned quantity
- unit: “s”
- LSB = 1/10 s ≈ 0.10 s
- value < = 51/2 s
I021/295/TI1 - Trajectory Intent Age
Age of the Trajectory Intent information, item I021/110
- 8 bits [
........
]- unsigned quantity
- unit: “s”
- LSB = 1/10 s ≈ 0.10 s
- value < = 51/2 s
I021/295/MAM - Message Amplitude Age
Age of the message amplitude, item I021/132
- 8 bits [
........
]- unsigned quantity
- unit: “s”
- LSB = 1/10 s ≈ 0.10 s
- value < = 51/2 s
I021/295/GH - Geometric Height Age
Age of the Geometric Height, item 021/140
- 8 bits [
........
]- unsigned quantity
- unit: “s”
- LSB = 1/10 s ≈ 0.10 s
- value < = 51/2 s
I021/295/FL - Flight Level Age
Age of the Flight Level, item I021/145
- 8 bits [
........
]- unsigned quantity
- unit: “s”
- LSB = 1/10 s ≈ 0.10 s
- value < = 51/2 s
I021/295/ISA - Intermediate State Selected Altitude Age
Age of the Intermediate State Selected Altitude, item I021/146
- 8 bits [
........
]- unsigned quantity
- unit: “s”
- LSB = 1/10 s ≈ 0.10 s
- value < = 51/2 s
I021/295/FSA - Final State Selected Altitude Age
Age of the Final State Selected Altitude, item I021/148
- 8 bits [
........
]- unsigned quantity
- unit: “s”
- LSB = 1/10 s ≈ 0.10 s
- value < = 51/2 s
I021/295/AS - Air Speed Age
Age of the Air Speed, item I021/150
- 8 bits [
........
]- unsigned quantity
- unit: “s”
- LSB = 1/10 s ≈ 0.10 s
- value < = 51/2 s
I021/295/TAS - True Air Speed Age
Age of the True Air Speed, item I021/151
- 8 bits [
........
]- unsigned quantity
- unit: “s”
- LSB = 1/10 s ≈ 0.10 s
- value < = 51/2 s
I021/295/MH - Magnetic Heading Age
Age of the Magnetic Heading, item I021/152
- 8 bits [
........
]- unsigned quantity
- unit: “s”
- LSB = 1/10 s ≈ 0.10 s
- value < = 51/2 s
I021/295/BVR - Barometric Vertical Rate Age
Age of the Barometric Vertical Rate, item I021/155
- 8 bits [
........
]- unsigned quantity
- unit: “s”
- LSB = 1/10 s ≈ 0.10 s
- value < = 51/2 s
I021/295/GVR - Geometric Vertical Rate Age
Age of the Geometric Vertical Rate, item I021/157
- 8 bits [
........
]- unsigned quantity
- unit: “s”
- LSB = 1/10 s ≈ 0.10 s
- value < = 51/2 s
I021/295/GV - Ground Vector Age
Age of the Ground Vector, item I021/160
- 8 bits [
........
]- unsigned quantity
- unit: “s”
- LSB = 1/10 s ≈ 0.10 s
- value < = 51/2 s
I021/295/TAR - Track Angle Rate Age
Age of the Track Angle Rate, item I021/165
- 8 bits [
........
]- unsigned quantity
- unit: “s”
- LSB = 1/10 s ≈ 0.10 s
- value < = 51/2 s
I021/295/TI2 - Target Identification Age
Age of the Target Identification, item I021/170
- 8 bits [
........
]- unsigned quantity
- unit: “s”
- LSB = 1/10 s ≈ 0.10 s
- value < = 51/2 s
I021/295/TS - Target Status Age
Age of the Target Status, item I021/200
- 8 bits [
........
]- unsigned quantity
- unit: “s”
- LSB = 1/10 s ≈ 0.10 s
- value < = 51/2 s
I021/295/MET - Met Information Age
Age of the Meteorological Information, item I021/220
- 8 bits [
........
]- unsigned quantity
- unit: “s”
- LSB = 1/10 s ≈ 0.10 s
- value < = 51/2 s
I021/295/ROA - Roll Angle Age
Age of the Roll Angle, item I021/230
- 8 bits [
........
]- unsigned quantity
- unit: “s”
- LSB = 1/10 s ≈ 0.10 s
- value < = 51/2 s
I021/295/ARA - ACAS Resolution Advisory Age
Age of the latest update of an active ACAS Resolution Advisory, item I021/260
- 8 bits [
........
]- unsigned quantity
- unit: “s”
- LSB = 1/10 s ≈ 0.10 s
- value < = 51/2 s
I021/295/SCC - Surface Capabilities and Characteristics Age
Age of the information on the surface capabilities and characteristics of the respective target, item I021/271
- 8 bits [
........
]- unsigned quantity
- unit: “s”
- LSB = 1/10 s ≈ 0.10 s
- value < = 51/2 s
Notes:
- In all the subfields, the maximum value indicates “maximum value or above”.
I021/400 - Receiver ID
Definition: Designator of Ground Station in Distributed System.
Structure:
- 8 bits [
........
] - raw value
I021/RE - Reserved Expansion Field
Definition: Expansion
Structure:
Explicit item (RE)
I021/SP - Special Purpose Field
Definition: Special Purpose Field
Structure:
Explicit item (SP)
User Application Profile for Category 021
I021/010
- Data Source Identification
I021/040
- Target Report Descriptor
I021/161
- Track Number
I021/015
- Service Identification
I021/071
- Time of Applicability for Position
I021/130
- Position in WGS-84 Co-ordinates
I021/131
- High-Resolution Position in WGS-84 Co-ordinates
(FX)
- Field extension indicatorI021/072
- Time of Applicability for Velocity
I021/150
- Air Speed
I021/151
- True Airspeed
I021/080
- Target Address
I021/073
- Time of Message Reception for Position
I021/074
- Time of Message Reception of Position-High Precision
I021/075
- Time of Message Reception for Velocity
(FX)
- Field extension indicatorI021/076
- Time of Message Reception of Velocity-High Precision
I021/140
- Geometric Height
I021/090
- Quality Indicators
I021/210
- MOPS Version
I021/070
- Mode 3/A Code in Octal Representation
I021/230
- Roll Angle
I021/145
- Flight Level
(FX)
- Field extension indicatorI021/152
- Magnetic Heading
I021/200
- Target Status
I021/155
- Barometric Vertical Rate
I021/157
- Geometric Vertical Rate
I021/160
- Airborne Ground Vector
I021/165
- Track Angle Rate
I021/077
- Time of ASTERIX Report Transmission
(FX)
- Field extension indicatorI021/170
- Target Identification
I021/020
- Emitter Category
I021/220
- Met Information
I021/146
- Selected Altitude
I021/148
- Final State Selected Altitude
I021/110
- Trajectory Intent
I021/016
- Service Management
(FX)
- Field extension indicatorI021/008
- Aircraft Operational Status
I021/271
- Surface Capabilities and Characteristics
I021/132
- Message Amplitude
I021/250
- Mode S MB Data
I021/260
- ACAS Resolution Advisory Report
I021/400
- Receiver ID
I021/295
- Data Ages
(FX)
- Field extension indicator(spare)
(spare)
(spare)
(spare)
(spare)
I021/RE
- Reserved Expansion Field
I021/SP
- Special Purpose Field
(FX)
- Field extension indicator