1. Model Category

2. Summary

The ARC2000 project began in 1989, and is based on ideas that emerged from older projects such as ASTA (ATM Strategic and Tactical Advisor). The main assumption in ARC2000 is the availability of 4D-FMS and the ability for aircraft to fly almost exactly trajectories defined 25 minutes in advance. Controllers and sectors are virtually eliminated from the ARC2000 environment. Conflict resolution clearances are generated automatically on the ground and sent to aircraft using data-link. Consequently, ARC2000 does not provide Human Machine Interface (HMI) for controllers to manually exercise Air Traffic Control, even though the simulation is displayed on a high-resolution 29'' screen used in ATC. However, a significant element that spun off the ARC2000 project is HIPS, (Highly Interactive Problem Solver), developed by the EEC. This is an interactive conflict resolution aid based on 4D-FMS capabilities that may be used either by controllers, or by pilots in the case of a decentralized conflict resolution scheme. This tool will be tested in the forthcoming European experiments PHARE Demos 1 and 3.

The Major features of ARC2000 are:

• Control instructions are prepared automatically and delivered by the system to aircraft via data-link.
• ARC2000 essentially handles direct flights from zone entry to exit, although it can accommodate non-direct routings.
• Navigation is based on pseudo flight plans where constraints are specified in lieu of a formal flight plan (RNAV traffic):
  • most of the traffic is overflying;
  • a significant proportion of flights depart from or enter pseudo-terminal areas with metering down to predefined levels over specified points.
• Disturbances include:
  • activation/deactivation of Temporary Reserved Areas (TRAs);
  • flight path deviations using either the Multi-aircraft Cockpit Simulator (MCS) or predefined data for specific aircraft.
• All aircraft are assumed to be equipped with a 4D Flight Management System. Possible degradation of aircraft capability or air-ground exchange are not taken into consideration for the first demonstration. However, the decision-aid derivative HIPS can account for degraded aircraft capabilities.
• The coordination process between the ARC2000 area and adjacent centres (en-route or terminal) is simplified.
• A generally stable and organised (conflict-free) air traffic situation existing at the beginning of any simulation is maintained in that state over the duration of the simulation.
• The goal of ARC2000 is to re-establish a stable organised air-traffic situation when an unforeseen event disturbs a certain amount of flight selectively over a certain period of time.

3. Input Requirements

• The simulated airspace which consists of two main elements:
  1. the en-route area where ARC2000 technology is implemented (the dimensions of this area must provide sufficiently long flying times (greater than one hour) permitting a strategic approach of air traffic control);
  2. the adjacent airspaces (below and around).
  The area currently simulated is delimited by the Northern part of Spain and Portugal, the Western part of France and the southern part of Great Britain and Ireland.
• The traffic sample. In EEC (Eurocontrol Experimental Centre) simulations the traffic samples come from a recorded period of a peak day of 1989. The recorded flights have been concentrated with respect to start time (and also cloned when necessary) within a period of 2 hours in order to create two different traffic samples of respectively 508 and 750 aircraft, allowing the possibility of simulating in real-time two different types of traffic densities and complexities.
• The manoeuver priorities and associated parameters.
• The sequencing points and associated parameters. Note that sequencing can only be done at waypoints or arrival/departure routes.
• The deviation thresholds (the ARC2000 system monitors the aircraft positions, in order to verify that the aircraft fly their predicted trajectories, and, if not, to take actions).
• The lateral separations that apply between aircraft. The separation standards are aircraft- and speed- dependent and have been adapted to take in account the real-life imperfections of 4D-FMS. This may result in separation standards that are higher than the ones currently in use.
• The vertical separations.
• The time horizon for conflict resolution.
• The alteration to apply on the air system positions.

4. Outputs

• the aircraft density in the airspace;
• the conflict density in the airspace;
• trajectory deviations;
• unsolved conflicts;
• extra route distance;
• etc ... .

5. Major Assumptions

6. Computational Characteristics

• Hardware Requirements: The system runs on a HP 9000/755 machine, but in principle, it could run on any machine in the 700 series, since PA-RISC 1.1 machine code was generated. The display position requires two screens equipped with PEX 5.0 servers. The supervision position requires one screen equipped with an X11 release 5 server. The screen used are 29" wide.
• Software Requirements: The ARC2000 software was written in ADA and ANSI-C and is divided into component sub-systems. There are 28 identifiable sub-systems spread over 1041 files. There are 301,093 lines of code, of which:
  • 4,465 lines of C code;

  • 167,004 lines of ADA code;

  • 66,194 lines of comment;

  • 63,430 blank lines.

  The display software uses Xlib and PEXlib software. The supervision position used X- toolkit and Motif library software.

• Execution Characteristics: A typical simulation with 506 aircraft and 3 hours of traffic lasts 3 hours.

• Documentation: The following documents are available from EEC (at Bretigny France):
  • `ARC2000 TECHNICAL REPORT' Task AS06 EEC Report : 274 (December 1994). Aside from ARC200 specific information, this document contains a detailed description of BADA (basic aircraft performance database) in use in many of the European ATC fast-time and real-time simulation facilities, such as NARSIM in the Netherlands.

  • `ARC2000 USER GUIDE' (July 1995)

  • `ARC2000 SOFTWARE SPECIFICATION 2.0' 1992

  • `ARC2000 PARAMETERS' Task AS10 Internal EEC note: 3/B2.1/1995

  • A flyer describing the main features of ARC2000

  • An overview of ARC2000 Version 3 from the operational point of view, EEC Report: 286 (1.15.1996)

7. Learning Effort

8. Modularity and Flexibility

9. Status

10. Extent of Model Verification

11. Principal Applications

12. Availability

13. Contacts and information for model evaluation

Frédérique Ayache
email: aya@eurocontrol.fr

14. Summary Evaluation