Attachment 9 - SBIS Oceanic ADS B Service Spec 05 18 2021.pdf

U.S. Department of Transportation

Federal Aviation Administration

Surveillance and Broadcast Services Program

Oceanic Requirements

Version 2.0

Informational Draft

May 18, 2021

Federal Aviation Administration 600 Independence Avenue, SW

Washington, DC 20591

Contents 1 Introduction

1.1 Background

1.2 Purpose

1.3 Scope

2 References

3 Definitions

4 Assumptions

5 Challenges

6 Functional Requirements

6.1 ADS-B

6.1.1 Inputs

6.1.2 Processing

6.1.3 Outputs

6.2 PWAM

6.2.1 Inputs

6.2.2 Processing

6.2.3 Outputs

6.3 Security

7 Performance Requirements

7.1 Service Volume Definitions

7.2 ADS-B

7.2.1 Capacity

7.2.2 Integrity

7.2.3 Position Update Interval

7.2.4 Latency

7.2.5 Independent Validation Performance

7.2.6 Availability

7.3 PWAM

7.3.1 Capacity

7.3.2 Position Update Interval

7.3.3 Probability of False Target Detection

7.3.4 Accuracy of Reported Position

7.3.5 Altitude Reliability and Validation

7.3.6 Latency

7.3.7 Target Acquisition Time

7.3.8 Time of Applicability Accuracy

7.3.9 Availability

7.3.10 Accuracy of Reported Track Velocity

8 Acronyms

1 Introduction

1.1 Background

The Federal Aviation Administration (FAA)’s Surveillance and Broadcast Services (SBS) Program has introduced Automatic Dependent Surveillance–Broadcast (ADS-B) based services into the National Airspace System (NAS). Some of these services may be provided by satellite-based infrastructures in oceanic airspace. Services include:

• Automatic Dependent Surveillance-Broadcast (ADS-B) - ADS-B messages broadcast by aircraft over the 1090 MHz Extended Squitter (1090ES) data link are received by the space-based infrastructure and delivered to ATC for use in separation assurance and other services. The ADS-B messages can also be received by other aircraft to support cockpit-based applications.

Note: The other data link approved for use in the NAS is the Universal Access Transceiver (UAT) defined in DO-282B. The FAA would be interested in potential support for the UAT data link as well.

• Passive Wide Area Multilateration (PWAM) – Three or more receivers on different satellites measure the time-of-arrival of the same ADS-B and available Mode S, messages.

Aircraft position is determined by joint processing of the time-difference-of-arrival (TDOA) measurements computed between a reference and the receivers measured time-of-arrival at a central location. Only one message need be received at 3 or more receivers within an update interval for accurate position determination. Aircraft identity and barometric altitudes are determined by decoding the ADS-B and corresponding Mode S messages. PWAM will only require passively acquired messages, without any interrogation stimulus.

1.2 Purpose

This document provides the Federal Aviation Administration (FAA)’s Surveillance and Broadcast Services Program’s current vision of evolving FAA requirements for ADS-B in oceanic airspace.

This document is provided for informational purposes only and not intended as a Request for Proposal. This document does not represent the full set of requirements for ADS-B as a service and is subject to change.

1.3 Scope

This document provides space-based ADS-B service requirements and optional requirements for

PWAM.

2 References

1. 14 CFR Part 91, Automatic Dependent Surveillance-Broadcast (ADS-B) Out Performance Requirements To Support Air Traffic Control (ATC) Service; Final Rule, Department of Transportation, Federal Aviation Administration, Friday, May 28, 2010

2. DO-260B - Minimum Operational Performance Standards for 1090 MHz Extended Squitter Automatic Dependent Surveillance – Broadcast (ADS-B) and Traffic Information Services – Broadcast (TIS-B), December 2009, RTCA

3. DO-260C - Minimum Operational Performance Standards for 1090 MHz Extended Squitter Automatic Dependent Surveillance – Broadcast (ADS-B) and Traffic Information Services – Broadcast (TIS-B), December 17, 2020, RTCA

4. DO-303 - Safety, Performance, and Interoperability Requirements Document for the ADS-B Non- Radar-Airspace (NRA) Application, December 13, 2006, RTCA

5. DO-318 - Safety, Performance, and Interoperability Requirements Document for Enhanced Air Traffic Services in Radar-Controlled areas Using ADS-B Surveillance (ADS-B-RAD), September

9, 2009, RTCA

6. DO-181F - Minimum Operational Performance Standards For Air Traffic Control Radar Beacon System/Mode Select (ATCRBS/Mode S) Airborne Equipment, December 17, 2020

7. *DO-282B - Minimum Operational Performance Standards for Universal Access Transceiver

(UAT) Automatic Dependent Surveillance – Broadcast (ADS-B), RTCA

8. NAS-IR-82530001, Surveillance and Broadcast Services (SBS) Service Delivery Point (SDP) to ATC Automation and Service Monitoring User Subsystems Interface Requirements Document, FAA

9. Federal Information Processing Standards Publication, Pub 199, Standards for Security Categorization of Federal Information and Information Systems, National Institute of Standards and Technology, U.S. Department of Commerce, February 2004

10. Security and Privacy Controls for Information Systems and Organizations, Draft NIST Special Publication 800-53 Revision 5, Joint Task Force, August 2017

*Note: RTCA is currently working on DO-282C.

3 Definitions

ADS-B Message: An ADS-B message is an expression of the ADS-B aircraft information in a data link specific format broadcast from aircraft. ADS-B messages are transmitted and received on either the UAT or 1090ES data links, per the formats defined in the Minimum Operational Performance Standards (MOPS) documents, RTCA/DO-282B and RTCA/DO-260B/DO-260C, respectively. In Oceanic Service Volumes, ADS-B messages will be only on the 1090ES data link.

ADS-B Report: ADS-B information concerning a single aircraft expressed in a data link independent format and exchanged between non-RF systems. An ADS-B Report is derived from one or more ADS-B Messages received on either the UAT or 1090ES data link. The ADS-B Report is provided in the FAA CAT033 Report format detailed in NAS-IR-SBS SDP.

ADS-B Service: The ADS-B service as used in this document applies to the component of the Surveillance and Broadcast Services ground infrastructure and satellite-based infrastructure that receives ADS-B messages, processes them, and distributes them in the form of ADS-B reports to the SDPs.

Service Volume: The FAA orders ADS-B and related services in service volumes defined in terms of an altitude floor, altitude ceiling, and multiple latitude/longitude vertices. For purposes of this document, the Service Volume (SV) is the volume in which the performance of the service satisfies the service requirements in this document.

Latency: Latency is the elapsed time from the TOMR of the first message received by the service until the output of the first bit of the corresponding target report at the SDP.

Service Delivery Point: The Service Delivery Point (SDP) is the physical demarcation point for the ADS- B service. ADS-B reports and service status reports are delivered by the ADS-B services to the SDP. The specific SDPs for each service volume will be defined by the FAA. Each ADS-B service volume will have one or more SDPs. The interface between the ADS-B service and the SDP is defined in NAS-IR-82530001.

Virtual Radio: In space-based infrastructures, all reporting (ADS-B reports, test target reports, status reports) is done through a configured virtual radio for the service volume. Each virtual radio will be uniquely identified by an assigned System Identification Code SAC/SIC code and service volume identifier.

The virtual radio represents the collective equipment, processes, and functions of the satellite-based ADS- B system providing ADS-B service in space-based infrastructures.

WAM Target Report: Multilateration derived information concerning a single target. A WAM Target Report is derived from one or more ADS-B Messages received on 3 or more satellites. The WAM Target Report is provided to the SDP in the FAA ASTERIX CAT010 format as defined in NAS-IR-82530001.

4 Assumptions It is assumed that aircraft will be equipped as required for oceanic airspace.

5 Challenges The following are some potential challenges:

1. Many non-TCAS II/ACAS X aircraft have bottom mounted antennas only, making detection by satellite based receivers a challenge.

2. The environment or system could introduce constraints, including:

a. Spectrum congestion near high-traffic airspace

b. Communications bandwidth

3. These contraints may introduce obstacles in meeting the following required surveillance performance:

a. Required update intervals

b. Report integrity (potential garbled messages)

4. Not all aircraft in the environment are ADS-B equipped, as oceanic airspace is generally not currently covered by any ADS-B mandates.

6 Functional Requirements

6.1 ADS-B

The ADS-B service inputs, processing, and outputs functional requirements are presented in the following sections.

6.1.1 Inputs

The ADS-B service receives and decodes ADS-B messages on the 1090ES data link, per applicable RTCA documents.

1. The ADS-B service shall receive and decode Version 2 (TWO) and Version 3 (THREE) ADS-B messages on the 1090ES data link, per DO-260B and DO-260C.

6.1.2 Processing

The following sections cover the requirements to convert ADS-B messages to reports, perform independent validation, and provide status information to support maintenance and monitoring.

6.1.2.1 Message to Report Conversion

ADS-B avionics convey information in multiple types of ADS-B messages. The information received in some messages is to be stored for inclusion in future ADS-B reports. ADS-B reports are created for output when an ADS-B message containing position information or indication of an emergency condition is received.

1. The ADS-B service shall retain the most recently received data element in ADS-B messages for each aircraft for an amount of time adaptable for each data element.

Note: Data elements are, for example, call sign, latitude, longitude, Mode A code.

2. The ADS-B service shall map the data received in ADS-B messages to reports in the FAA CAT033 format.

3. The ADS-B service shall create an ADS-B report when an ADS-B message containing position information or indication of an emergency condition is received.

6.1.2.2 Independent Validation

Validation is the process of performing a check on whether or not the position information reported in an ADS-B message from a particular aircraft could reasonably have been transmitted from the reported location.

1. The ADS-B service shall validate ADS-B reported position using an independent reference.

2. The ADS-B Service shall set the validation data element in each ADS-B report per the results of the independent validation.

6.1.2.3 Maintenance and Monitoring Processing

The ADS-B service must provide reports that provide status information to support maintenance and monitoring activities.

6.1.2.3.1 Test Targets

Test target ADS-B messages are injected into ADS-B receivers and reports are constructed from the messages to provide ongoing verification that the receivers are properly functioning.

1. The ADS-B service shall inject test target messages into each ADS-B receiver.

2. The ADS-B service shall construct a test target report for service volume.

6.1.2.3.2 Status Reports

The details on each of the following status reports are specified per NAS-IR-82530001.

1. The ADS-B service shall construct FAA ASTERIX CATEGORY 023 service volume context service status reports for each service volume.

Note: This report contains service volume status and statistics.

2. The ADS-B service shall construct FAA ASTERIX CATEGORY 023 equipment context service status reports for each service volume.

Note: This report contains status information for radio receivers in the service volume.

3. The ADS-B service shall construct service prediction reports in ASTERIX CATEGORY 238 for each service volume in space-based infrastructures.

Note: This report contains information on predicted future outages.

4. The ADS-B service shall construct ASTERIX CATEGORY 025 reports containing status of the space-based system components providing the ADS-B service in each service volume.

Note: This report contains status information on components providing the space-based ADS- B service.

5. The ADS-B service shall construct reports that contain Two-Line Element (TLE) parameters and the status of the satellites providing the ADS-B service in ASTERIX CATEGORY 253 reports in space-based infrastructures.

Note: This report contains information on satellite status and position.

6.1.3 Outputs

The ADS-B service sends reports to Service Delivery Points (SDPs) located in each facility that is to receive ADS-B data. SDPs serve as the demarcation point between the ADS-B service and the FAA systems.

1. The ADS-B service shall interface to FAA systems per NAS-IR-82530001.

2. The ADS-B service shall send FAA ASTERIX CATEGPORY 033 ADS-B reports created in each service volume to service delivery points identified for that service volume.

Note: ADS-B reports are sent for aircraft and test targets.

3. The ADS-B service shall send FAA ASTERIX CATEGORY 023 service status reports in each service volume to service delivery points identified for that service volume.

4. The ADS-B service shall send ASTERIX CATEGORY 238 service prediction reports for each service volume to service delivery points identified for that service volume.

5. The ADS-B service shall send status of the space-based system components providing the ADS-B service in ASTERIX CATEGORY 025 reports to service delivery points identified for that service volume.

6. The ADS-B service shall send reports that contain Two-Line Element (TLE) parameters and the status of the satellites providing the ADS-B service in ASTERIX CATEGORY 253 reports to service delivery points identified for that service volume.

6.2 PWAM

PWAM could provide surveillance for separation services if GPS is not available and could also be used to validate position information. The PWAM service inputs, processing, and outputs functional requirements are presented in the following sections.

6.2.1 Inputs

The PWAM service receives and decodes ADS-B messages on the 1090ES data link, per applicable RTCA documents.

1. The PWAM service shall receive and decode Version 2 (TWO) ADS-B messages on the 1090ES data link, per DO-260B and DO-260C.

2. The PWAM service shall receive and decode Mode S replies on the 1090 data link, per DO-181F.

6.2.2 Processing

1. The PWAM Service shall utilize a timing reference to calculate TDOAs and perform position estimation.

2. The PWAM Service shall generate the horizontal position for a target report by multilaterating on the 1090ES messages (squitters).

3. The time of applicability in a report shall be equal to the TOMR of the message used to determine the position included in the report.

4. The PWAM Service shall store information received in WAM Messages per Table 4-2.

5. The PWAM Service shall retain the most recently received value of each parameter in Table 4-2.

Note: Previous values of the parameters can be discarded when an update is received.

Table 4-1: PWAM Message Parameter Validity Time

Parameter / Contents Validity Time SPI 24 seconds

Mode 3/A Code 100 seconds Pressure Altitude 10 seconds

Note: A parameter is considered valid if a message has been received containing the data associated with this parameter. If an update has not been received within the indicated validity time, then there is no longer a valid value for this parameter.

6.2.3 Outputs

The PWAM Service outputs reports over interfaces to Service Delivery Points (SDP).

1. The PWAM Service shall provide the following report types for each PWAM Service Volume:

a. WAM Target Reports within the Service Volume,

b. PWAM Service Status Reports for the Service Volume.

2. The PWAM Service shall output WAM Reports in the FAA CAT010 format as defined in NAS-

IR-82530001.

6.3 Security

The SBS system is categorized as High Impact, per FIPS PUB 199.

Security controls, per NIST 800-53 Rev 5 for a system categorized as High Impact shall be implemented.

7 Performance Requirements The following sections provide an overview of service volume definitions, followed by the performance requirements. The ADS-B service performance requirements are assessed on a per service volume basis.

7.1 Service Volume Definitions

The FAA procures ADS-B services in service volumes with the following characteristics:

• Type of Service Volume o ADS-B services

• Service Volume Dimensions o Defined in terms of an altitude floor, altitude ceiling, and multiple latitude/longitude vertices

• Service Domain o Oceanic

• Traffic Density and Equipage Scenario o Low, medium, or high density (see Table 5-1)

• Independent Validation Required o Yes

• Service Delivery Points o Destination FAA facilities

• Data Links o 1090ES

Table 5-1 Traffic Density Environments

Traffic Density Total Traffic Count Maximum ES Maximum UAT Oceanic - Low 360 360 0

Oceanic - Medium 680 680 0 Oceanic - High 1000 1000 0

7.2 ADS-B

The ADS-B performance requirements are presented in the following sections.

7.2.1 Capacity

The ADS-B service must process the maximum number of aircraft in the service volume, as defined by the specified traffic density environment.

The ADS-B service shall have the capacity to process and deliver ADS-B reports for at least the specified traffic density for the service volume.

7.2.2 Integrity

ADS-B report integrity is defined in terms of the probability that the ADS-B service introduces an error into an ADS-B report, given that the ADS-B service is supplied with correct source data in ADS-B messages.

1. The probability that the ADS-B service introduces any error into an ADS-B report received at an SDP shall be less than 10-5 per Report.

7.2.3 Position Update Interval

Update interval refers to the time between two successive ADS-B reports for a particular aircraft that are based on the reception of ADS-B messages containing position information.

1. To support oceanic procedural separation standards, the ADS-B Service shall provide for each aircraft an ADS-B Report containing position information with an update interval no greater than

15.0 seconds (95%) at each SDP.

2. To support 5 NM separation services in a radar environment, the ADS-B Service shall provide for each aircraft an ADS-B Report containing position information with an update interval no greater than 8.0 seconds (97%) at each SDP.

3. To support 5 NM separation services in a non-radar environment, the ADS-B Service shall provide for each aircraft an ADS-B Report containing position information with an update interval no greater than 10.0 seconds (95%) at each SDP.

4. The ADS-B Service shall provide for each aircraft an ADS-B Report containing position information with an update interval no greater than 30.0 seconds (99.9%) at each SDP.

7.2.4 Latency

The space-based infrastructure 700 milliseconds latency has been assessed for en route and oceanic separation standards only at this time.

1. The maximum delay between the reception of the last bit of an ADS-B message, initiating an ADS- B report, and the reception of the first bit of the corresponding ADS-B report at the Service Delivery Point shall be less than or equal to 700 milliseconds in space-based infrastructures.

7.2.5 Independent Validation Performance

Performance requirements for current independent validation techniques are provided below for each environment. In the terrestrial environment, techniques include comparison with radar reported position, Time Difference of Arrival (TDOA), and passive ranging (on UAT only). In space-based infrastructures TDOA and beam validation techniques are used.

1. The ADS-B service shall determine the validation status of ADS-B reported position for each ADS- B equipped aircraft within 36 seconds (99%) from the initial ADS-B report time of reception, and within 36 seconds of a change in validation status.

7.2.6 Availability

The ADS-B service is safety-critical, and requires high availability to support air traffic control separation services.

1. The ADS-B service shall meet a minimum availability of 0.99996.

7.3 PWAM

The PWAM performance requirements are presented in the following sections.

7.3.1 Capacity

1. The PWAM Service shall provide the processing capacity to support the target counts specified for each PWAM Service Volume.

7.3.2 Position Update Interval

The PWAM position update interval is the maximum allowed time between successive WAM Reports containing position information that are sent to each SDP for a specific aircraft.

2. The PWAM Service shall provide for each aircraft in the En Route domain a WAM Report containing position information with an update interval no greater than 10.0 seconds (95%) at each

SDP.

3. The PWAM Service shall provide for each aircraft in the Oceanic domain a WAM Report containing position information with an update interval no greater than 15.0 seconds (95%) at each

SDP.

7.3.3 Probability of False Target Detection

1. The probability of false target detection shall be less than 1 in 1000 (< 0.1%) for all aircraft within a service volume.

7.3.4 Accuracy of Reported Position

1. The positional error measured shall not exceed ±1010 feet for the 95TH percentile for en route non-radar service volumes.

7.3.5 Altitude Reliability and Validation

1. The PWAM Service shall correctly report the aircraft altitude greater than 99% of the time.

2. The reported validation status shall be Valid in a minimum of 95% of the reports where the Mode C code or altitude is correct.

3. The reported validation status shall be Valid in a maximum of 1% of the reports where the Mode C code or altitude is not correct

7.3.6 Latency

1. The PWAM Service latency from the time of receipt of the first bit of an ADS-B or reply message to the time the first bit of a target report is received at the SDP shall be less than or equal to 700 ms.

7.3.7 Target Acquisition Time

1. The PWAM Service shall detect a target and output a corresponding target report within 15 seconds

(95%) after the target enters the defined Service Volume for oceanic domains.

7.3.8 Time of Applicability Accuracy

1. The reported time of applicability shall be within ± 1/128 seconds relative to the actual UTC position time of applicability when the service is synchronized with the GNSS.

7.3.9 Availability

1. The PWAM Service shall meet a minimum Availability of 0.99996.

7.3.10 Accuracy of Reported Track Velocity

1. The reported track velocity error shall not exceed ±10 meters/second for the 95th percentile.

8 Acronyms

1090ES 1090 MHz Extended Squitter ADS-B Automatic Dependent Surveillance-Broadcast CAT033 ASTERIX Category 33 Data Format (ADS-B Surveillance Messages) CAT23 ASTERIX Category 23 Data Format (Maintenance Monitoring Status Messages) CAT33 ASTERIX Category 33 Data Format (ADS-B Surveillance Messages) FAA Federal Aviation Administration MOPS Minimum Operational Performance Standards NAS National Airspace System NM Nautical Mile RTCA Radio Technical Commission for Aeronautics SAC/SIC System Area Code/System Identification Code SBS Surveillance Broadcast Services SDP Service Delivery Point sec Second(s) SV Service Volume OR State Vector OR System View TDOA Time Difference of Arrival TLE Two-Line Element UAT Universal Access Transceiver OR User Acceptance Test WAM Wide Area Multilateration PWAM Passive Wide Area Multilateration

6.1.3 Outputs

6.3 Security

8 Acronyms