1. Model Category

2. Summary

RAMS provides a flexible airspace simulation environment where a broad variety of new concepts may be tested at the desired level of detail. Due to the flexible design of RAMS, the system is capable of carrying out planning, organizational, high-level, or in-depth studies of a wide range of ATC concepts. This design includes 4-dimensional flight profiles, conflict detection and conflict resolution mechanisms, workload models, modern user interfaces and a data preparation environment.

RAMS offers an integrated simulation study environment, with many advanced features to assist the user in the development, simulation and analysis of an ATC system.

Models that may compete with RAMS include TAAM, ASIM, and, to a lesser degree, SIMMOD.

3. Input Requirements

• Rule-based resolution system: RAMS may work with or without automatic conflict resolution. It may also run in real- time, and a human controller can then interact with the software. When running in automatic mode, each controller in RAMS may be attributed a specific set of rules (the basic ATC conflict resolution rulebase contains over 100 rules) that RAMS will use for automatic conflict resolution. These rules may be defined sectorwise to account for local habits and working conditions.
Conflict probes can use a variety of conflict alert zone shapes. The basic shapes are rectangles, circles, ellipsoids, diamonds and users are required to select one of these only.
The separation values applied to aircraft are defined by any one of a number of sources, including the required controller separation, wake turbulence, oceanic flight metering fixes and the relative geometry of the flights in a conflict. All these features are optional and may be modified by the user.

• Flight plan description: RAMS offers the capability of simulating the entire flight plan in as much detail as desired. It can also generate flight plans automatically: Given a cruising altitude, the origin and the destination of a flight, RAMS can generate a flight plan with a climb path and a descent path based on specific aircraft performance. Aircraft performance is currently coded on lookup tables.

• Workload analysis: A virtually unlimited number of tasks may be defined for workload analysis purposes.

• Weather patterns - Special use airspace: Convective weather patterns and Special Use Airspace can be accounted for via time- varying forbidden zones.

4. Outputs

• Distribution of workload over centers, sectors, and individual control positions;
• Traffic loads within each sector/center overall and per route, level band, point, classified according to cruise, climb and descent;
• Penalties imposed upon traffic resulting from imposing ATFM measures, flight level changes, en-route/ground delays, and arrival holding.
• Frequency distribution based on many iterations of a given scenario (Monte-Carlo simulations).

Users of RAMS have mentioned however that RAMS post-processing capabilities are rather poor. The feeling is that the output is mainly made of large, unprocessed output files (trajectories, conflict start and end times).

CSSI seems to have developed a graphical tool based on SDAT, an interactive airspace building tool, to post-process some of RAMS' outputs. The contact name at CSSI is Stephane Mondoloni.

5. Major Assumptions

6. Computational Characteristics

• Software Requirements: RAMS comprises over 160,000 lines of ModsimII. Machines with 256 Mb of RAM or higher and a disk of 4 Gb or more are recommended for serious use of the system. MODSIM II is a fully object oriented simulation language developed by CACI Products Company that generates C code. It runs under UNIX under X-windows or its HP-Vue Window equivalent. The source code is not available to any users.

• Execution Characteristics: Typical speeds can range from 3 to 20 times real-time, depending on the desired simulation. Very small simulations may run up to 100 times real-time. FAA users have reported that it took 10 hours to run a 1-day, 12,000 flight simulation without conflict resolution.

• Documentation: According to the FAA users, the documentation to users is "adequate", and the graphical user interface is "adequate to good". A future site for RAMS information, documentation, online user support, users group and News/Discussion forum will be defined soon.

7. Learning Efforts

8. Modularity and Flexibility

9. Status

Current RAMS users include Eurocontrol Experimental Center, FAA/OR Washington, AENA Madrid, Transport Canada. Demands for RAMS have been received from CENA (France), Irish CAA, NATS (UK), DFS Frankfurt and MIT. A first RAMS user's group meeting is planned for June 1996.

10. Extent of Model Verification

11. Principal Applications

12. Availability

13. Contacts

Frank Jelinek
RAMS External Client Support
Model Development Team (MDV)
BP 15
91222 Bretigny sur Orge cedex
France
Tel: (1) 69 88 73 93
Fax: (1) 60 85 15.04\
Email: frank.jelinek@eurocontrol.fr

RAMS support team
Email: ramssupport@eurocontrol.fr
Web: http://www.eurocontrol.fr/~mdv

Contacts in the United States:

Mr. Steve Bradford
FAA
(202) 358 5234
sbradford@mail.hq.faa.gov

Mr. Stephane Mondoloni
CSSI
(202) 488-0003
Stephane.Mondoloni@mail.hq.faa.gov

14. Report sources

15. Summary Evaluation