Asterix category 021 - ADS-B Target Reports
category: 021
edition: 0.25
date: 2005-03-01
Preamble
Surveillance data exchange. ADS-B Target Reports.
Description of standard data items
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).
I021/020 - Emitter Category
Definition: Characteristics of the originating ADS-B unit.
Structure:
8 bits [
........
]values:
1: Light aircraft <= 7000 kg
2: Reserved
3: 7000 kg < Medium aircraft < 136000 kg
4: Reserved
5: 136000 kg <= 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: Reserved
24: Reserved
I021/030 - Time of Day
Definition: Time of applicability (measurement) 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
The time of the day value is reset to zero at every midnight.
I021/032 - Time of Day Accuracy
Definition: The maximum difference between the actual time of applicability of the reported position and the time reported in the Time of Day item (I021/030).
Structure:
- 8 bits [
........
] - unsigned quantity
- unit: “s”
- LSB = 1/28 s ≈ 3.91e − 3 s
I021/040 - Target Report Descriptor
Definition: Type and characteristics of the data as transmitted by a system.
Structure:
I021/040/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/RAB - Report Type
1 bit [
.
]values:
0: Report from target transponder
1: Report from field monitor (fixed transponder)I021/040/SAA - Selected Altitude Available
1 bit [
.
]values:
0: Equipment capable to provide Selected Altitude
1: Equipment not capable to provide Selected AltitudeI021/040/SPI - Special Position Identification
1 bit [
.
]values:
0: Absence of SPI
1: Special Position IdentificationI021/040/(spare)
- 1 bit [
.
]I021/040/ATP - Address Type
3 bits [
...
]values:
0: Non unique address
1: 24-Bit ICAO 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: Unknown
1: 25 ft
2: 100 ftI021/040/(spare)
- 3 bits [
...
]
I021/080 - Target Address
Definition: Target address (emitter identifier) assigned uniquely to each target.
Structure:
- 24 bits [
........................
] - raw value
I021/090 - Figure of Merit
Definition: ADS figure of merit (FOM) provided by the aircraft avionics.
Structure:
I021/090/AC - ACAS Capabilities
2 bits [
..
]values:
0: Unknown
1: ACAS not operational
2: ACAS operartional
3: InvalidI021/090/MN - Multiple Navigation Aids
2 bits [
..
]values:
0: Unknown
1: Multiple Navigation not operational
2: Multiple Navigation operartional
3: InvalidI021/090/DC - Differencial Correction
2 bits [
..
]values:
0: Unknown
1: Differencial Correction
2: NO Differencial Correction
3: InvalidI021/090/(spare)
- 6 bits [
......
]I021/090/PA - Position Accuracy
- 4 bits [
....
]- signed quantity
- LSB = 1
- Note:
-
bits-4/1 (PA) code the “Navigational Uncertainty Categories – Position” as described in the ADS-B MASPS [Ref. 3]
I021/095 - Velocity Accuracy
Definition: Velocity uncertainty category of the least accurate velocity
Structure:
- 8 bits [
........
] - raw value
- Note:
-
bits-8/1 code the “Navigational Uncertainty Categories – Velocity” as described in the ADS-B MASPS [Ref. 3]
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: Calculated Position in WGS-84 Co-ordinates with a resolution of 180/(2^25) degrees.
Structure:
I021/130/LAT - Latitude
- 32 bits [
................................
]- signed quantity
- unit: “°”
- LSB = 180/225 ° ≈ 5.36e − 6 °
- value > = − 90 °
- value < = 90 °
I021/130/LON - Longitude
- 32 bits [
................................
]- signed quantity
- unit: “°”
- LSB = 180/225 ° ≈ 5.36e − 6 °
- value > = − 180 °
- value < 180 °
Notes:
- Positive longitude indicates East. Positive latitude indicates North.
- The LSB provides a resolution at least better than 0.6m.
I021/140 - Geometric Altitude
Definition: Vertical distance between the target and the projection of its position on the earth’s ellipsoid, as defined by WGS84, 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.
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 - Intermediate State Selected Altitude
Definition: The short-term vertical intent as described by either the FMS selected altitude, the Altitude Control Panel Selected Altitude, or the current aircraft altitude according to the aircraft’s mode of flight.
Structure:
I021/146/SAS - Source Availability
1 bit [
.
]values:
0: No source information provided
1: Source Information providedI021/146/SRC - 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
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
1: ActiveI021/148/AH - Altitude Hold Mode
1 bit [
.
]values:
0: Not active
1: ActiveI021/148/AM - Approach Mode
1 bit [
.
]values:
0: Not active
1: ActiveI021/148/ALT - Altitude
- 13 bits [
.............
]- signed quantity
- unit: “ft”
- LSB = 25 ft
- value > = − 1300 ft
- value < 100000 ft
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:
- 16 bits [
................
] - unsigned quantity
- unit: “kt”
- LSB = 1 kt
I021/152 - Magnetic Heading
Definition: Magnetic Heading (Element of Air Vector).
Structure:
- 16 bits [
................
] - unsigned quantity
- unit: “°”
- LSB = 360/216 ° ≈ 5.49e − 3 °
I021/155 - Barometric Vertical Rate
Definition: Barometric Vertical Rate, in two’s complement form.
Structure:
- 16 bits [
................
] - signed quantity
- unit: “ft/min”
- LSB = 25/22 ft/min ≈ 6.25 ft/min
I021/157 - Geometric Vertical Rate
Definition: Geometric Vertical Rate, in two’s complement form, with reference to WGS-84.
Structure:
- 16 bits [
................
] - signed quantity
- unit: “ft/min”
- LSB = 25/22 ft/min ≈ 6.25 ft/min
I021/160 - Ground Vector
Definition: Ground Speed and Track Angle elements of Ground Vector.
Structure:
I021/160/GS - Ground Speed in Two’s Complement Form Referenced to WGS84
- 16 bits [
................
]- signed 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
- 16 bits [
................
]- unsigned quantity
- unit: “°”
- LSB = 360/216 ° ≈ 5.49e − 3 °
I021/165 - Rate Of Turn
Definition: Rate of Turn, in two’s complement form.
Structure:
Extended item.
I021/165/TI - Turn Indicator
2 bits [
..
]values:
0: Not available
1: Left
2: Right
3: StraightI021/165/(spare)
- 5 bits [
.....
]
(FX)
extension bit
0: End of data item
1: Extension into next extentI021/165/ROT - Rate of Turn
- 7 bits [
.......
]- signed quantity
- unit: “°/s”
- LSB = 1/22 °/s ≈ 0.25 °/s
- value < = 15 °/s
(FX)
extension bit
0: End of data item
1: Extension into next extent
- Notes:
-
- A positive value represents a right turn, whereas a negative value represents a left turn.
- Value 15 means 15 °/s or above.
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:
8 bits [
........
]values:
0: No emergency / not reported
1: General emergency
2: Lifeguard / medical
3: Minimum fuel
4: No communications
5: Unlawful interference
I021/210 - Link Technology Indicator
Definition: Indication of which ADS link technology has been used to send the target report.
Structure:
I021/210/(spare)
- 3 bits [
...
]I021/210/DTI - Cockpit Display of Traffic Information
1 bit [
.
]values:
0: Unknown
1: Aircraft equiped with CDTII021/210/MDS - Mode-S Extended Squitter
1 bit [
.
]values:
0: Not used
1: UsedI021/210/UAT - UAT
1 bit [
.
]values:
0: Not used
1: UsedI021/210/VDL - VDL Mode 4
1 bit [
.
]values:
0: Not used
1: UsedI021/210/OTR - Other Technology
1 bit [
.
]values:
0: Not used
1: Used
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/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
I021/030
- Time of Day
I021/130
- Position in WGS-84 Co-ordinates
I021/080
- Target Address
I021/140
- Geometric Altitude
I021/090
- Figure of Merit
(FX)
- Field extension indicatorI021/210
- Link Technology Indicator
I021/230
- Roll Angle
I021/145
- Flight Level
I021/150
- Air Speed
I021/151
- True Airspeed
I021/152
- Magnetic Heading
I021/155
- Barometric Vertical Rate
(FX)
- Field extension indicatorI021/157
- Geometric Vertical Rate
I021/160
- Ground Vector
I021/165
- Rate Of Turn
I021/170
- Target Identification
I021/095
- Velocity Accuracy
I021/032
- Time of Day Accuracy
I021/200
- Target Status
(FX)
- Field extension indicatorI021/020
- Emitter Category
I021/220
- Met Information
I021/146
- Intermediate State Selected Altitude
I021/148
- Final State Selected Altitude
I021/110
- Trajectory Intent
(spare)
(spare)
(FX)
- Field extension indicator(spare)
(spare)
(spare)
(spare)
(spare)
I021/RE
- Reserved Expansion Field
I021/SP
- Special Purpose Field
(FX)
- Field extension indicator