Federal AviationAdministration

AP23 briefing on D4:

Draft Proposal for a second set of GS/AS Applications

ASAS-GN Seminar13 Nov 08, Rome

ByBrian Baxley, NASABen Stanley, Helios

2Federal AviationAdministration 2

Objective of this presentation

To outline a methodology for developing future, long-term ASAS applications based on ADS-B

To show how and why AP23 has developed the work

To highlight how to use the document and next steps to be taken

3Federal AviationAdministration 3

AP23 Overview: Deliverables

Five deliverables from AP23: D1 – General data exchange D2 – Methodology to prioritize applications for AP23 D3 – Operational Role of Airborne Surveillance in Separating

Traffic D4 – Draft proposal for a second set of ADS-B/ASAS

applications D5 – Draft White Paper on Issues Surrounding Airborne

Separation

4Federal AviationAdministration 4

AP23 D4: GS/AS Applications (V0.3, Oct 08)

List of Chapters and Appendices

1. Introduction 2. Future Application Definition Process 3. Application Elements and Functions 4. Examples of Applications 5. Transition from “Package 1” to Future Applications 6. Way Forward Appendix A: Application Template Appendix B: Input from Stakeholders Appendix C: Application Element Mapping Appendix D: Element and Function Mapping Appendix E: Submitted Applications and Element Mapping

5Federal AviationAdministration 5

D4, Chapter 1Introduction

AP23 is focused on long-term ground and airborne surveillance (GS and AS) applications of common interest between FAA and Eurocontrol, and beyond those already covered by RFG

It looks to NextGen and SESAR to set the scope and direction

AP23 developed and documented a process to prioritize applications and functions

Possible applications

Ideas (including SESAR + NextGen)

Down-selection

Feasibility

6Federal AviationAdministration 6

D4 is not currently a list of proposed applications as per “Package 2”

D4: Is a draft proposal for advanced ASAS elements and

functions Shows how AP23 organised the applications, and

enhanced understanding of advanced applications Includes “functional decomposition” of applications into

building blocks Is a work in progress, represents “snapshot” of current

work

D4, Chapter 1Introduction: Objectives

7Federal AviationAdministration 7

Why? Elements and functions are used to streamline

standardisation rather than many applications in many environments, some

standardised elements and functions may be used leads to economical development and implementation

There is however an aim to highlight key applications such that all required elements and functions have their

requirements derived in the most demanding context beneficial, or necessary in terms of meeting the

performance goals of the future system way of showing that elements/functions can be put together

and that the approach works

D4, Chapter 1Introduction: Objectives

8Federal AviationAdministration 8

D4, Chapter 2Future Application Definition Process

4000 people solicited over 3 months (07/2007 – 09/2007) for ideas of future ASAS applications

Over 100 inputs received, with significant overlap in objective, operational use, requirements, and functions

Triggered new approach to find set of functions common to all ASAS applications regardless of environment

Resulted in grouping of: ATSA: Situational Awareness ASPA: Spacing ASEP: Separation SSEP: Self Separation Surface: Surface GS: Ground Surveillance

This briefing

9Federal AviationAdministration 9

Use AP23 D4

Application

elements

ASASFunctions

Environment

description

Candidate application description

Operational Requireme

nts

Applicability Area/Conditi

ons

Safety Requirement

s

Performance Requirement

s

Interoperability

Requirements

D4, Chapter 3Application Elements and Functions

Process to build an application: Elements + Functions +

Environment = Application

Application elements - A basic ASAS-enabled (operational) capability of the subject aircraft that cannot easily be subdivided further into more basic elements.

ASAS functions - the processes, calculations, and monitoring tasks that must be supplied by the ASAS avionics system to enable the application element.

Environments - en-route, procedural, terminal, and surface.

10Federal AviationAdministration 10

D4, Chapter 3Application Elements (1 of 5)

Objective: - Enabling Applications Identify Designated Aircraft Transfer Separation Responsibility Contingency Procedures

Contingency ProceduresTransfer Separation

ResponsibilityIdentify Designated Aircraft

11Federal AviationAdministration 11

D4, Chapter 3Application Elements (2 of 5)

Objective: Achieve Relative Position Target Point Merge Target Track Merge Dynamic Path Merge Pair-Wise Interval Achievement

Target Track Merge

Target Point Merge

Dynamic Path Merge

Pair-Wise Interval Achievement

12Federal AviationAdministration 12

D4, Chapter 3Application Elements (3 of 5)

Objective: - Maintain Relative Position Pair-Wise Interval Maintenance Track Follow Dynamic Path Follow

Target Follow

Pair-Wise Interval Maintenance

Dynamic Path Follow

13Federal AviationAdministration 13

D4, Chapter 3Application Elements (4 of 5)

Objective: - Maximize Use of Desired Trajectory Vertical Passing & Crossing Lateral Passing & Crossing Delegated Encounter User Request Manoeuvre Conflict Management Manoeuvre w/o Conflict

Conflict ManagementDelegated Encounter

Manoeuvre w/o Conflict

Lateral Passing & CrossingVertical Passing

& Crossing

User Request

14Federal AviationAdministration 14

Example surface application elements (draft) Runway crossing Runway incursion detection (and resolution) Taxi follow Taxi merge Autonomous take-off (in TM environment)

D4, Chapter 3Application Elements (5 of 5)

Runway Crossing

Taxi Merge

Taxi Follow

15Federal AviationAdministration 15

D4, Chapter 3ASAS Functions

ASAS functions - the processes, calculations, and monitoring tasks to enable the application element. There are: Traffic Data: identify & track aircraft, provide reference aircraft

trajectory, assess initiation/continuation/termination criteria Merge: compute manoeuvre to the merge, compute merge location Follow: compute dependant following trajectory Manage Interval: compute speed to achieve and maintain interval,

monitor interval conformance Separation Maintenance: monitor and maintain separation between

reference and subject aircraft Conflict Detection: probe trajectory for conflicts, alert crew to conflicts Conflict Resolution: vertical, lateral, or user-preferred trajectory to

ensure traffic separation Trajectory Optimization: compute conflict-free user-preferred

trajectory, compute manoeuvring flexibility

16Federal AviationAdministration 16

D4, Chapter 4Example of Application

Two examples to put together process, elements, and functions.

#1): Merging and Spacing with Separation ASEP M&S (PO-ASAS 3) Objectives:

Achieve Relative Position Maintain Relative Position

#2): Self-Separation Airborne Trajectory Management SSEP-AirTM (PO-ASAS 4) Objective:

Maximize Use of Desired Trajectory

17Federal AviationAdministration 17

D4, Chapter 4Example #1 of Application: ASEP M&S (1 of

2) NAME: ASEP M&S

Ground Set-Up Aircraft Operation

Crew receives clearance, selects lead aircraft, enters assigned spacing interval.

Crew verifies acceptable speed, then follows speed guidance

Crew follows speed guidance while merging the aircraft

18Federal AviationAdministration 18

D4, Chapter 4Example #1 of Application: ASEP M&S (2 of

2) Objectives:

Achieve Relative Position Maintain Relative Position

P2: Aircraft ID and Procedure Feasibility

P3: Clearance & Transfer of Responsibility

P4: ASEP M&S Procedure

P5: Procedure Complete

P6: Exceptions

P1: Set Up

Elements: Functions:

P2P3

Identify Designated Aircraft

Transfer Separation Authority

P4

Target Point Merge

Pair wise Interval Achievement

Pair wise Interval Maintenance

Track Follow

Transfer Separation Authority

P5

Contingency ProceduresP6

Identify reference aircraft

Track referenceaircraft

Provide reference aircraft trajectory

Assessing initiation criteria

P2P3

Compute maneuvers

to merge

Compute speeds to achieve and maintain interval

Compute dependent following trajectory

Monitor maintenance of separation

Compute guidance to maintain separation

Assessing continuation

criteriaP4

Assessing termination criteria P5

19Federal AviationAdministration 19

NAME: SSEP AirTM Ground Operations

Manage Airspace Resources

Generate Flow Constraints Manage Unequipped

Aircraft

Airborne Operations Broadcast State and Intent

Data Self-Separate from Traffic,

Weather, and Airspace Conform to Ground-

Generated Constraints (RTAs, etc)

Optimize Trajectory

En Route Airspace

Ground managed

Self-Separating

Next briefing, “NASA ASAS”

covers more detail

D4, Chapter 4Example #2 of Application: SSEP AirTM (1 of

2)

20Federal AviationAdministration 20

D4, Chapter 4Example #2 of Application: SSEP AirTM (2 of

2) NAME: SSEP-AirTM Objectives:

Maximize Use of Desired TrajectoryP1: Set Up Trajectory

P2: Responsibility Transfer

P3: Separation Prediction

P5: RBT Change Monitor

P7: Termination

P8: Exceptions

P6: Trajectory Revision

P4: Performance Monitor

AC approaches transfer point

AC continues along trajectory

Traj

ecto

ry c

hang

e re

quire

d

Current trajectory is acceptable

Elements: Functions:

P1P2

User requestedmaneuver

Transfer Separation Authority

P3P6

Conflict detectionAnd resolution

Maneuver withoutconflict

Transfer Separation Authority

P7

Contingency ProceduresP8

Probe trajectory for conflicts

Track referenceaircraft

Provide reference aircraft trajectory

Assessing initiation criteria

P1P2

Assessing termination

criteria P5

P3P6

Probe trajectory for conflicts

Monitor maintenance of separation

Compute guidance to maintain separation

Assessing continuation

criteria

Compute user-preferred

trajectory to provide separation

Alert crew for conflicts

Compute traffic-constrained

user-preferred trajectory

Compute aircraft

performances

Compute maneuvering

flexibility

21Federal AviationAdministration 21

D4: Way Forward

AP23 is proposing a set of ASAS elements and functions, a method to build applications, and how to apply this in a practical manner for NextGen and SESAR.

D4 stops short of proposing a firm set of applications for “Package 2” Engage with larger community to build key applications

Cost benefit analyses to be performed by stakeholder in specified scope and operational environment

Lots of validation now needed – to be identified in the next AP23 deliverable (D5 – issues for ASEP)

D4 is a work in progress, represents “snapshot” of current work

22Federal AviationAdministration 22

Thank you

brian.t.baxley@nasa.gov

ben.stanley@askhelios.com