Software Overview

1
Software Overview

• Michelle Eshow
• CTAS Software Development Group
• AOS Development Branch (AFD)

http//www.ctas.arc.nasa.gov
2
Outline

• Software Architecture and Process Summaries
• External Interfaces
• How Tools Share Software
• Aircraft Processing Attributes
• Aircraft Identification

3
CTAS Software Architecture

• Software comprises 14 independent executable
  processes
• Processes run in real-time in a distributed
  computing environment communicate via messages
  using TCP/IP
• Processes are classified as algorithmic, GUI, or
  communications-oriented
• Software is written in ANSI C and C for Solaris
  2.6 OS
• Software is currently 900K SLOC
• Site-specific adaptation is kept in separate data
  files current DFW adaptation for FAST is 114K
  lines
• 80 of software is shared for all tools

4
CTAS Software Architecture
External Interface Drivers
FAA Computers/ Displays
Weather Data Processing
Weather Data
Input Source Manager
Timeline GUI
TMA, E/DA only
Communications Manager
Planview GUI
Dynamic Planner
Profile Selector
Profile Selector Cntr
FAST only
Profile Selector Act
AFAST only
D2/EDA only
Trajectory Synthesizer
Trajectory Synthesizer
Trajectory Synthesizer
5
CSCI/Process Summary

• External Interface Drivers
• Convert external flight plan, track data into
  CTAS-readable format
• Send CTAS advisories back to FAA Host/ARTS
  computers
• Input Source Manager (ISM)
• Merges diverse streams of flight plan, track data
  into single stream
• Controls addition and deletion of aircraft from
  system
• Performs state filtering (ground speed, course,
  vertical speed)
• Communications Manager (CM)
• Routes all internal messages among CTAS processes
  as required
• Enables user to specify data sources and flight
  types to accept into system (via messages to ISM)
• Provides central status window and debugging
  interface
• Formats advisory data before it is sent back to
  Host or ARTS

6
CSCI/Process Summary (contd)

• Timeline GUI (TGUI)
• Provides time-based display of arriving traffic
  (ETAs, STAs)
• Provides load graphs with predictions of future
  traffic counts
• Is primary interface for TMCs, allowing input of
  scheduling constraints (Airport Config, AAR,
  runway blockages, etc.)
• Generates textual delay reports
• Planview GUI (PGUI)
• Provides planview of traffic, with overlay of
  metering list (TMA)
• Used by TMCs for TMA, pFAST
• Used as interface to D2, aFAST, EDP active
  advisories in advance of final FAA implementation
• Used to emulate PVDs or FDADs during simulation
• A primary tool for development and debugging

7
CSCI/Process Summary (contd)

• Trajectory Synthesizer (TS)
• Generates 4-D trajectory based on clients input
  horizontal waypoints and speed and altitude
  constraints
• Uses weather data (winds, temp, pressure)
• Uses aircraft model data (lift/drag, thrust,
  typical speeds, weights)
• Route Analyzer (RA)
• Uses TS to request multiple trajectories per
  aircraft based on aircraft state and adaptation
  specs (horizontal, speed DOFs)
• Generates range of possible ETAs to relevant
  reference points (meter fix, faf, runway) as
  specified by adaptation
• Generates analysis packets that are basis for PFS
  iteration
• Multiple RA/TS pairs are run in parallel to
  handle all traffic

8
CSCI/Process Summary (contd)

• Profile Selector (PFS)
• Generates runway assignment and landing sequence
  advisories for pFAST advisories sent to PGUI,
  FDADs
• Also generates STAs, but these are not used
  directly by controllers
• Uses RA analysis packets and adaptation to
  iterate to achieve desired runway balancing while
  minimizing conflicts
• Uses TS during iteration
• Profile Selector Active (PFS_A)
• Generates runway, sequence, heading, speed
  advisories for aFAST
• Uses pFAST adaptation plus additional elements
• Sequencing, deconfliction algorithms are combined
  to produce usable active advisories, a large
  improvement over PFS

9
CSCI/Process Summary (contd)

• Profile Selector Center (PFS_C)
• Generates advisories for Center tools DA, E/DA,
  D2
• Performs conflict prediction and formulates
  advisories for display on PGUI
• Generates Direct-to advisories for display on
  PGUI
• For DA, can generate trajectories and advisories
  to meet DP STAs
• Dynamic Planner (DP)
• Generates schedules for arrival aircraft for TMA
• Schedules are to Outer Fix, Meter Fix, FAF,
  Runway
• Performs runway allocation as a means to improve
  schedules (reduce delays)
• Responds to TMC constraints entered on TGUI

10
External Interfaces
Host
ARTS
ETMS
Host Interface Device
ARTS Gateway
Host Data Acquisition And Routing
ARTS Data Acquisition And Routing
ETMS Data Acquisition And Routing
Pseudo-Aircraft System (Simulation)
Input Source Manager
FAA Responsibility
NASA Responsibility
11
How Tools Share Software

• Each CSCI has superset of software that any tool
  needs
• PGUI has code to present TMA, pFAST, E/DA/D2,
  aFAST, or simulation planview display
• CM has code to communicate with PFS, PFS_C, and
  PFS_A
• At runtime, user specifies mode for process, eg
• pgui -data DFW_data -tma -default TMA
• CM has no specific mode just responds to
  whatever processes are attached. Messages
  intended for a process that is not attached are
  dropped on the floor.
• Much testing effort is dedicated to assuring no
  unintended side effects of one tool on another in
  a process

12
Aircraft Processing Attributes

• User can specify source (Host, ARTS) and types of
  traffic (arrivals, overflights, departures)
  allowed into CTAS, independent of tool
• Able to generate ETAs for all traffic types
• Host AK route used for Center portion of flight
  plan CTAS route parsing used for some D2
  functions
• TMA, FAST scheduling applies to arrivals to
  CTAS-adapted airports
• TMA schedules to outer fix, meter fix, final
  approach fix, runway
• No current capability to schedule to arbitrary
  points or to display ETAs/STAs to other points

13
Aircraft Identification

• ISM associates flight plans received from various
  sources to determine whether they are for same
  aircraft
• Assumes callsigns can change and can differ among
  sources
• Uses CID to associate an ARTS feed with its
  primary Host (allows pop-ups for ARTS-only
  aircraft)
• Keeps callsigns for display separate from
  aircraft search key, which does not change all
  GUIs display callsign of current track source
• Multi-Center scheme design in progress
• Use callsign, departure fix, destination to
  associate flight plans from different Centers
  some heuristics may be needed
• Assume an ARTS feed has CIDs from only 1 Host
  (allow multiple Host and ARTS feeds)