Sarcophilus harrisii
In the wild, its main food supply consists of small wallabies and kangaroos, birds, lizards and probably frogs and crayfish. It is not hesitant to attack animals much larger than itself. Despite a ferocious reputation, the little "devils" have proven to be easily tamed and indeed, have become affectionate and playful companions. They sometimes exhibit a savage and fierce appearance and although they growl and scream, are not really very mean. Being nocturnal, they typically hunt and feed during the night. Driven by the continual overpowering urge to eat, this slobbering, snarling, omnivorous tornado with teeth does not care what he gobbles. It demolishes everything in his path, leaving behind a trail of rubbish and reducing whole forests to toothpicks in seconds [1,2].
The above describes Sarcophilus harrissi or Tasmanian Devil, Bugs Bunny's evil nemesis, or a typical fighter pilot on combat survival training. But more pertinently, Tasmanian Devil also refers to an ongoing simulation experiment in the distributed mission training domain.
Distributed Mission Training
Distributed mission training (dmt) is a general term that refers to the ability to conduct mission-level training at geographically disparate locations. When applied to aircraft training, it includes the capability to conduct basic engaged maneuvers and to link multiple aircraft simulators together to develop complex team fighting concepts. It can also include full mission training in a simulated combat environment at the basic employment-formation level [3]. Training of this type is of keen interest to both the U.S. Navy and the U.S. Air Force. Existing training systems do not offer the capability to train in multi-ship roles and at distributed locations. Resource constraints and safety considerations also limit the use of aircraft sorties to meet this training need. The application of advanced simulation technology is envisioned to provided for an increase in this vital aspect of flight training.
The U.S. Air Force initiated the Distributed Mission Training (DMT) program in early 1997 to advance Air Force training in the dmt domain [3]. The U.S. Navy also has similar activities surrounding its use of simulation technology for this domain. For the remainder of this discussion, "dmt" refers to the general distributed mission training domain rather than this specific U.S. Air Force or any other specific service program.
Tasmanian Devil Project
In Fiscal Year 1999, the Defense Modeling and Simulation Office (DMSO), the Air Force Research Laboratory Warfighter Training Research Division (AFRL/HEA), and the US Navy Air Combat Environment Test and Evaluation Facility (ACETEF) Aircraft Simulation - Manned Flight Simulator (MFS) began a cooperative effort involving the application of HLA to distributed mission training. This project - Tasmanian Devil - was designed to gain experience in the application of HLA. Two separate federations were designed and implemented following a common federation design process and using a single Federation Object Model (FOM). The culmination of these efforts was two federation demonstrations in December of 1999. These demonstrations illustrated the technical feasibility of HLA to support distributed mission training. A second phase for this project will continue into Fiscal Year 2000 and focus on improving federation robustness, management, and performance.
The federations
The Tasmanian Devil (Taz) project included the development of two separate federations, in the context of a single federation development process. One federation was developed at the MFS facility at Patuxent River, MD, and the second federation was developed at the AFRL facilities in Mesa, AZ. A diagram of these federations is presented in figure 1.
Taz Federations
Both federations shared an identical Federation Object Model (FOM), and a number of federates. The JSAF federate was included to represent threat aircraft, SAM sites, and missiles. A JSAF GUI was also used to support an AWACS role player. The ASTI radio federates were used to model communications between cockpits, between cockpits and AWACS role players, and to technical controllers. Also used during federation integration and testing were the DMSO Data Collection Tool (DCT), and the Federation Management Tool (FMT). Site-specific federates included F-16 Viper cockpit simulators and a Director Control Station (DCS) at AFRL, and F-18 cockpit simulators and an Ordnance Server at MFS.
Federation Development
The development of the Taz federations proceeded under the auspices of the HLA Federation Development Process (FEDEP). The FEDEP is a systems engineering process that guides the entire life-cycle of an HLA federation development [4]. Steps in this process include defining federation objectives, developing a federation conceptual model, designing the federation, developing the federation, integrating and testing the federation, and finally executing the federation and analyzing results. Although defined in stages, these steps of the FEDEP were iterated as necessary to allow the federations to progress successfully. Phase I of Taz included the first five steps of the FEDEP. The next phase will continue additional federation development, testing, and eventual federation execution and analysis. A detailed discussion of the stages of the FEDEP process as viewed by the Taz development is include in a paper being presented at the March 2000 Simulation Interoperability Workshop [5].
Federation Execution
At the culmination of Taz phase I, demonstrations were held at both the AFRL and MFS facilities. A single scenario was used including two defending aircraft versus a specific incoming threat. The scenario was designed to protect friendly airspace against incoming penetrations.
Observations from Phase I
The first phase of the Taz federation demonstrated the technical feasibility HLA offers to support a dmt type of federation. Specific findings include:
The use of the HLA was successfully demonstrated in a high-fidelity, war fighter-in-the-loop air-to-air training environment. RTI-NG was successfully applied to this federation development. A single FOM was demonstrated to support different services and different federations. The FEDEP process was shown to be useful for developing these federations.
The interested reader is invited to read the spring SIW 2000 paper on the Tasmanian federation to learn more about these observations, and about phase I of the Taz federation [5].
Future Plans
A second phase of the Taz project will continue into FY00. This effort will focus on continuing the development from phase I, with a concentration on robustness, management, and performance issues of the federation. The primary goal for this second phase is to extend the demonstration into the operational aspects of applying HLA in the distributed mission training domain.
Contact Information:
John Tufarolo The MITRE Corporation 1820 Dolley Madison Blvd. McLean, VA 2210 tufarolo@mitre.org
AFRL/HEA http://www.williams.af.mil/ ACETEF MFS http://www.nawcad.navy.mil/acetef/mfs/index.html
References
[1] World Wide Web (2000). Tasmanian Devil Information, http://www.nature.ca/notebooks/english/tasdevil.htm
[2] World Wide Web (2000). Tasmanian Devil Information, http://www.isource.net/<sweetpea/batscave/looneytunes/taz.html
[3] Distributed Mission Training (1999). The Journal, Training Systems Product Group, ASC/YW, Wright-Patterson AFB, December.
[4] Defense Modeling and Simulation Office (1999). High Level Architecture Federation Development and Execution Process (FEDEP) Model, Version 1.4, June.
[5] Zabek, A., Bebbe, B., Barbier, G., and DiCola, J. (2000). Tasmanian Devil: An Application of the High Level Architecture in the Distributed Mission Training Domain, to appear in proceedings of the 2000 Spring Simulation Interoperability Workshop, March.