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This thesis concerns the potential use of auditory virtual reality (A VR) in safety-critical situations. Localization accuracy is essential in many VR situations, such as simulated cockpits, where vision is fully occupied and targets must be signified acoustically. However, the errors reported for localizing 3D sounds varies considerably in the literature and some (e.g. Wightman & Kistler, 1989; Wenzel et aI, 1993) report fairly large errors. This thesis consists of an evaluation of the use of acoustic cues to indicate the location of certain targets. A Knowles Electronic Manikin for Acoustic Research (KEMAR) was used to examine the effects of individualized pinnae on localization accuracy. The results showed that using our own pinnae over foreign pinnae provides little or no benefit. More surprisingly, substantial errors were observed in this study. This initial result drove the fundamental investigation into the large angle errors. The method of eliciting subject responses was investigated. The findings established response method as an important methodological feature in localization experiments from the significant effect it has on the results. Error values can be halved when using a categorical method, compared to an unguided (non-categorical) method, possibly because it constrains the subjects' response options. A further possible constraint on subject responses is the effect of memory in absolute judgement tasks. If the memory of one sound impinges on subsequent sounds then the subject's judgement is constrained and the measurement of error may be contaminated. This effect was studied by introducing variable delays that should affect memory .(0 a different extent. No obvious differences in accuracy were noted. This rules out 'interstimulus interval' as a cause for the variability of reported angle errors. Stimulus types were varied in an effort to maximise acuity. Although broadband sounds are purported to give the smallest errors (e.g. Stevens & Newman, 1936; Sandel et aI, 1955), this investigation offered a unique comparison of long and shortduration broadband and complex sounds. But consistently high angle errors forced the inclusions of non-acoustic cues such as vision and head movements, which decreased the error to between 0° and 7°. III The implicatioos for VR in light of the importance of vision (demonstrated by this work), are that it is 'not advisable to implement an auditory cueing system that may conflict or fail to be guided by vision. Where high levels of accuracy are required, as is paramount in safety-criticalsituations, auditory localizatioo is not sufficient as a sole cue to target location. Scientific conclusion: The acoustic cues alone (independent of context) cannot support accurate auditory localization. Applications conclusion: It is not advisable to implement an auditory cueing system that is not guided by vision.

What we once thought of as purely civilian considerations are today increasingly significant matters to international peace and security. Conflicts within states and urban encounters make civilian considerations particularly troublesome for military forces sent to stabilize that country. Along with these changes in the patterns of war, the techniques that are used in operations have also changed. Stability operations are an application of military power to influence the political and civilian environment. Often these take the specific form of peacekeeping or peace support operations. Peace Support Operations (PSO) are military operations to support, provide and sustain a long-term political settlement. PSO and conventional war have different characteristics. It is possible to generalize the main purpose of conventional war as "defeat the enemy," whereas peacekeeping attempts to "win the peace." At tactical level, some of the goals of peacekeeping missions are to help and protect civilians, to avoid violence and escalation, and to ensure the safety of the public with civilians in a stability operation than in combat. Secondly, stability operations are executed in a more diverse range of environments than those of conventional war. Furthermore, depending upon the mandate, soldiers must use different sets of engagement rules when interacting with civilians.

The author proposes an architecture based on the Dynamic Actor Layer and the Game Manager in Delta3D to create a Networked Virtual Environment which could be used to train Navy Officers in tactics, allowing team training and doctrine rehearsal. The developed architecture is based on Object Oriented and Modular Design principles, while it explores the flexibility and strength of the Game Manager features in Delta3D game engine. The implementation of the proposed architecture is planned to be done in standard personal computers running's WindowsTM OS, but as Delta3D is a multiplatform tool, the generated code can be easily ported to Linux or even MacTM platforms. The designed architecture includes also a proposal for fast scenario creation and modification based on XML technology.

Human performance in spatial orientation tasks is mainly determined by spatial awareness and the skills to transition from the current spatial attitude into the desired spatial orientation and position. Erroneous spatial awareness may lead to degraded task performance, to the loss of equipment, to serious injuries, or fatal aviation mishaps. The use of UAVs is considered beneficial due to the reduction in risk to the human carrying out the "mission". However, the remote execution of such a mission is extremely demanding for the operator. If extensive use of UAVs is to become routine, a number of concerns that may influence their effective use needs to be addressed. When we consider the human-in-the-loop (HITL), then vehicle control and the use of autonomy are important issues for the end user. Therefore this thesis will investigate the use of a virtual avatar in the flight simulator software (Weber Box) and conduct experimental proof of concept (conduct of experiments and analysis, evaluation and validation of the data of the concept using actual flight simulation software). Results of a study (conducted by Weber, 2006) indicated that the proposed design (Weber Box) seemed to strongly support spatial awareness in 3D orientation tasks. Time to assess a spatial situation decreases significantly, whereas accuracy of this spatial judgment at least maintains its level. This study investigated human orientation performance in relation to display designs that support mental models of the user's spatial situation under varying workload conditions. The main goal is to support the pilot/operator with intuitive, 3D-based information which improves their spatial awareness and supports their mental model of spatial position, he/she is operating under, even with varying workload conditions. As a follow-up study has to be identified, determining whether varying workload affects performance between the two display designs, and if there is a significant difference to a set of properties which are essential for linking virtual avatars and spatial awareness.

This thesis explores the addition of Artificial Intelligence (AI) capability to the Delta3D Gaming and Simulation engine developed at the Naval Postgraduate School. A look at what types of AI capabilities exist and their potential to add value to the project is presented. This look includes the use of specific AI technologies, such as State Machines and Pathfinding, as well as the potential use of existing open source packages. One growing trend in the commercial game industry is the use of AI Middleware packages, allowing developers to buy what technologies they need and reduce development time. This thesis covers the link between AI and animation, specifically comparing how animation is handled by Delta3D and UnrealEngine. One final area covered is the use of scripting to generate behaviors within a game or simulation. Again, UnrealEngine, specifically UnrealScript, is considered as a potential model for a scripting language based on the Python programming language. Python was chosen based on its integration with the underlying C++ base code. By following the game industry's lead, one has a pool of potential options and avoids attempting to reinvent the wheel.

With the aim of creating a skill trainer of conceptual knowledge, what is the development process for ensuring the correct set of objectives are determined, matched to appropriate technology, and implemented? Months and years prior to the first instance of trainer use, the initial steps of the developer determine the end product s success. Computer based trainers fielded for use by the military are rife with poorly matched tasks to technology, often the product of contracts that begin with a list of high-level objectives imitating a detailed requirements document. In those cases, software developers are forced to make best guesses about how to meet those objectives. Is there a better method? We embarked on a project to create a trainer for the military aviation mission of Forward Air Control (Airborne) using a development process that first identified critical tasks, then matched technology to facilitate training those tasks, and finally allowed expert evaluation of positive transfer. We do not assume that our methodology which foregoes a comprehensive transfer study is the preferred approach; rather, in cases where such a study is not feasible, we assert that a good development process, reinforced with subsequent expert evaluation, is a comparable alternative.

Agent technology is widely deployed in numerous commercial areas such as networking, modeling, and software; however, this technology remains under-utilized by operational organizations within the United States Navy. This thesis will investigate the importance of artificial intelligence (AI) for military training simulations, particularly in the training of intelligence personnel in the Navy. The Computer Generated Forces (CGF) of the current Intelligence Team Trainer's (ITT) system initiate actions as a result of rigid scripted programming. Forces will execute the same actions regardless of what the user decides to do, resulting in highly unrealistic scenarios. For instance, in a scenario where an ARG (Amphibious Ready Group) transits the Strait of Hormuz, the response of Iranian P3 or an incoming dhow would be the same whether the battle group utilized frigate escorts or not. This thesis will produce very simple, but less rigid AI, which can easily be made more complex and intelligent in later phases. Demonstrations and assessments will validate the importance of AI integration for the ITT. Furthermore, this analysis of the requirements for the AI will assist training commands and combat information centers fleet wide with the range of realistic combat-related possibilities needed in order to ensure a fully capable 'combat ready' watch team.

Fleet maneuvers, or division tactics (DIVTACS), are achieved by a series of precision shipboard movements directed by an Officer in Tactical Control. Much like a precision drill team, DIVTACS training requires multiple ships underway in close proximity, often a rare commodity. Costs to conduct live training range from several Thousand (per evolution) to several Million dollars (to repair ships after a collision at-sea). Computer simulation opens the door to maximizing DIVTACS training, while mitigating risk. The Navy spends in excess of 60 Million dollars per year on simulation-based training. Currently available simulators provide a DIVTACS capability by connecting several simulators together via a LAN. These simulators are cost prohibitive ranging from 1,00,000 dollars to Millions of dollars per unit. They are manpower and maintenance intensive requiring dedicated infrastructures, drastically limiting deploy-ability and reliability. Open source applications are gaining considerable leverage in the commercial market and offer significant cost-reductions. This thesis explored the possibilities of open source development by providing a proof of concept division tactics simulator. Additional considerations were given to the extension of the simulator for use in surface tactics in general and areas of future research.

Visualizing operations environments in three dimensions (3D) supports the warfighters' ability to make rapid, well-informed decisions by presenting complex systems in a naturalistic, integrated display format. Unfortunately, constructing these environments is a time-consuming task requiring specific expertise not typically available in the command center. The future use of 3D visualization in military operations depends on the ability of personnel with minimal graphics experience to create virtual environments quickly and accurately by leveraging data-driven customization of content from model archives with the data available in the command center. Practical 3D visualization depends on standardized scene autogeneration. The Extensible 3D (X3D) Graphics family of specifications is approved by the International Standards Organization (ISO) as the Web-based format for the interchange and rendering of 3D scenes. Previous work has demonstrated that an archive of X3D scenes, such as the Scenario Authoring and Visualization for Advanced Graphical Environments (SAVAGE) library, can be used to autogenerate sophisticated 3D tactical environments. Assembling and making sense of the data necessary to autogenerate a 3D environment requires context and good documentation, best accomplished through metadata. Metadata also supports data-centric, component-based design; key philosophies in promoting interoperability of networked applications. Coupled with recent developments in X3D, enhanced features of the Savage X3D Model archives are now sufficiently mature to support rapid generation of tactical environments. This thesis proposes an XML metadata standard to collect and organize the information necessary to create and populate a tactical 3D virtual environment: the Savage Modeling and Analysis Language (SMAL). The logical extension of a well designed standard is the ability to cross the boundaries of usage, allowing simulators to share data with command and control (C2) suites and mission planning tools based on the construction of a virtual scene. SMAL provides the informational "glue" necessary to perform tactical modeling, simulation, and analysis using networked, physics-based X3D virtual environments.