ED Decision 2008/004/R
Summary of ADS-B-NRA Airborne Safety and
Performance Requirements
|
Parameter |
Requirement |
|
Horizontal Position and Horizontal Position Quality Indicator(s) |
10-5/fh |
|
ADS-B System Continuity |
2*10-4/fh |
|
Horizontal Position Latency[39] |
1.5 sec/95% |
Table 1:
Overall Minimum Airborne ADS-B System[40]
Requirements
|
Parameter |
Requirement |
|
Horizontal Position Source |
|
|
—
Accuracy (95%) |
—
5 NM Sep: 926 m |
|
—
Integrity |
|
|
—
Containment Radius (Rc) |
—
5 NM Sep: Rc=2 NM |
|
—
Source Failure Probability |
10-4/h[41] |
|
—
Alert Failure Probability |
10-3 (per position source failure
event) |
|
—
Time to Alert |
—
5 NM Sep: 10 sec |
Table 2:
Minimum Horizontal Position Source Requirements
Note: for DO-260 based ADS-B transmit
systems, the related encoding of the horizontal position quality indicator
through the Navigation Uncertainty Category (NUC) effectively leads to a
containment radius requirement of 1NM for a 5 NM separation service.
Note: accuracy and integrity containment
radius requirements are expressed here as guidance to related horizontal
position source regulation (refer to section 8.4).
Note: the containment bound requirements
reflect the outcomes of both the collision risk assessment (CAP) and
time-to-alert assessment.
Note: the accuracy and integrity
containment radius requirements have to be met by the horizontal position
source, taking into account the effects of on-board latency (if not
compensated for).
An uncompensated latency of 1.5 seconds
translates into a dilution in the order of 450 metres (assuming an aircraft
speed of 600 knots in en-route airspace). This value of 450 metres has to be
added to the actual performance of the horizontal position source(s), the sum
of which has to be within the required bounds.
The GNSS equipment specified in 8.4.6
meets the overall accuracy and integrity requirements, including the effects
of an uncompensated latency of maximum 1.5 second accumulated up to the time
of transmission.
|
Parameter |
Requirement |
|
Barometric Altitude |
—
Accuracy: as per the installed sensors (refer to section 8.5.2) —
Maximum
Latency: 1 sec (as for SSR) |
|
Aircraft Identification, SPI, Emergency Status |
As for SSR [AMC20-13]. |
Table 3:
Other Minimum ADS-B Surveillance Data Requirements
|
Parameter |
Loss |
Corruption |
Note |
|
Barometric Altitude |
Minor |
Minor |
As for SSR [AMC20-13]. |
|
Aircraft Identification |
Minor |
Minor |
As for SSR.[AMC20-13] |
Table 4:
Failure Condition Categories
[Amdt 20/3]
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