The warfighter constantly needs increased accuracy from GPS and a means to increasing this accuracy to the decimeter level is a broadcast ephemeris message containing GPS satellite orbit and clock corrections. The ephemeris message is produced at the GPS MCS (Master Control Station) which receives GPS signal data from NGA and Air Force worldwide and uses sophisticated software to produce the orbit and clock corrections. The problem is getting the ephemeris message to the tactical user in a forward operating area. This thesis proposed a notional architecture for pushing the ephemeris message to the tactical user. It then modeled the architecture and simulated the broadcast of the ephemeris message to a tactical user using NETWARS. The baseline architecture was simulated and analyzed and then additional constraints were placed upon the network to simulate a real-world model. The simulation results demonstrated that the architecture was feasible for ephemeris message broadcast with the constraints on time intervals between broadcasts, residual traffic and message size.

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 use of fractionated spacecraft systems in on-orbit spacecraft assembly has the potential to provide benefits to both the defense and civil space community. To this end, much research must be conducted to develop and prove the requisite technologies to achieve these benefits. This thesis contributes to that effort by presenting the design and system integration, operating procedures and software development for a prototype three Degrees-Of-Freedom (DOF) Spacecraft Simulator. This simulator will be used in the Proximity Operations Simulator Facility, as part of the Naval Postgraduate School's Spacecraft Robotics Laboratory, to simulate autonomous guidance, navigation and control (GNC) for spacecraft proximity operations and assembly within the framework of the Autonomous Multi-Agent Physically Interacting Spacecraft project. The new spacecraft simulator includes several key enhancements over the previous Autonomous Docking and Spacecraft Servicing Simulator (AUDASS) developed in 2005 including a smaller and more agile structure, reduced air consumption and a Miniature Single-Gimbaled Control-Moment-Gyroscope (MSGCMG) to provide the necessary torque about the rotation axis. The MSGCMG in the simulator is a low-cost, low-mass, easily controlled momentum exchange device with a high torque to required power ratio. Furthermore, it provides the vehicle with high slew-rate capability, a key measure of performance in on orbit spacecraft assembly. Simulation and experimental results are presented for the prototype AMPHIS vehicle, demonstrating a potential slew-rate of 4.8 deg/s for a 30 degree rest-to-rest maneuver. The ultimate goal of this thesis is to provide the design specifications, combined with the necessary documentation and software development, for the prototype vehicle of the testbed for the AMPHIS project. The work conducted in fabricating the prototype vehicle will enable rapid fabrication of two additional vehicles which will provide an essential hardware-in-the-loop capability for experimentation with evolving control algorithms, sensors and mating mechanisms to be used for autonomous spacecraft assembly.

The Configurable Fault Tolerant Processor (CFTP) team at Naval Postgraduate School (NPS), Monterey, was created to develop, test, and implement reliable computing solutions for the space environment. The CFTP team seeks to design reliable circuits using Field Programmable Gate Arrays (FPGA) to include designs that mitigate the radiation hazards posed to FPGAs. A significant challenge faced by the CFTP team has been the integration and subsequent software development of the CFTP architecture, which includes a "Controller" and an "Experiment" FPGA. This thesis investigates some of the specific design issues that must be considered for future experiments, to include timing between the two FPGAs, and data throughput of the CFTP architecture. Procedures for the development and implementation of experiments are detailed for the benefit of future experimenters who may be new to designing for FGPAs. Lastly, the Controller program is streamlined such that only minor modifications are required by prospective users in order to conform to specific experiments. Over the years the CFTP team has produced several experiments that will provide reliable computing solutions for the space environment. Now, in addition to the "what" is to be used in space, this thesis presents "how" to run them in space.

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.

There are two main purposes to this thesis study. First, we will deploy the principles of software development that we have learned through the Software Engineering track here at NPS and test its validity through the development of a real world system. This system will be a completely self sustaining prototype of a web design containing both the front end and back end requirements. Second, we will conduct a study of Human Computer Interaction (HCI) through the design and usability testing of a new interactive uniform regulations manual. All military services currently possess their own individual uniform regulations specific to each service. This system, although it will be specific to the United States Marine Corps, can be used as a model for any other service as well as any international military desiring a similar solution to the inherent problems associated with current manuals. The new system will address all aspects currently outlined in the regulations. This regulation will be used by all US civilians and military service members to whom the current manual is now relevant. Although we fully intend to deliver a finished product to the Marine Corps for their official use, the true value to us as students is in the process of developing and testing this new system. The knowledge learned here will benefit us in any future system design or development projects.

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.

Software Visualization can play a significant role in our fight against Software's inherent complexity. Despite all efforts made so far, Software Visualization tools have not succeeded to be a part of Software Engineers everyday practice. We believe that a properly defined taxonomy that will provide a framework for discussion, analysis and research guidance by offering a systematic and systemic overview of the area, covering all the concerns and challenges, is a starting point for a new approach for the field. After analyzing existing taxonomies and exploring existing tools, we approach Software Visualization as an interface between humans and software and we propose a multi-layered framework that incorporates all the concerns and the challenges of our field, in a neat, systematic and expandable way that can also serve as a roadmap for a research area and that can promote communication of existing and new ideas.

Air Traffic Control (ATC) is a complicated domain in which many specialists should collaborate and communicate with each other in order to guarantee safe and efficient air traffic. A significant number of air traffic control errors are associated with either faulty coordination between ATC actors, or a failure of some kind of team coordination. These errors are likely to increase in the future as aircraft density increases. Many researchers suggest that the introduction of team and teamwork concepts during the training phase of the ATC actors will be in help to reduce the amount of these errors. The objective of this research is to conceive, design, and implement a teamwork-oriented Air Traffic Control simulator that can be easily installed and used in ATC schools. The product of this thesis will be a complete software package that allows trainees in the different ATC specialties to work together in the same manner as they do "on-the-job" in order to collaboratively manage an air traffic situation. This type of simulator should allow air traffic control trainees to acquire more robust coordination skills and reduce the amount of traffic control errors caused by lack of teamwork in actual ATC training situations. / Tunisian Air Force author.

As software systems increase in size and complexity, so does the need to predict and control scope, schedule, and costs. The United States General Accountability Office has acknowledged weaknesses in the software acquisition process. Industry data indicates that improving the software development process can have significant effect on a project team's ability to generate products within planned scope, schedule, and cost estimates. This thesis focus is on software maintenance, one phase of the Army's acquisition process, to demonstrate that stronger management practices are needed to make better predictions and assessments in those areas. Two software maintenance projects were evaluated for success in project management performance against CMMI practices. This research results in a set of recommendations and predicted benefits are provided for use by the organization as input to the next process improvement effort. / US Army (USA) author.