A formula for the average fade time of the intensity of a spherical optical wave travelling through atmospheric turbulence is developed. The model employed involves isotropic, homogeneous statistics using a lognormal distribution for the channel. The analysis is based on the fact that the logarithm of the irradiance is normally distributed and uses the work of S. O. Rice who developed such an expression for a zero mean, Gaussian process. The analysis employs the covariance function and the Taylor frozen turbulence hypothesis which results in an expression for the autocorrelation function.

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No description available.

Team coordination is vital to the success of team missions. On the battlefield and in other hazardous environments, mission outcomes are often very unpredictable because of unforeseen circumstances and complications encountered that adversely affect team coordination. In addition, the battlefield is constantly evolving as new technology, such as context-aware systems and unmanned drones, becomes available to assist teams in coordinating team efforts. As a result, we must re-evaluate the dynamics of teams that operate in high-stress, hazardous environments in order to learn how to use technology to enhance team coordination within this new context. In dangerous environments where multi-tasking is critical for the safety and success of the team operation, it is important to know what forms of interaction are most conducive to team tasks. We have explored interaction methods, including various types of user input and data feedback mediums that can assist teams in performing unified tasks on the battlefield. We’ve conducted an ethnographic analysis of Soldiers and researched technologies such as sketch recognition, physiological data classification, augmented reality, and haptics to come up with a set of core principles to be used when de- signing technological tools for these teams. This dissertation provides support for these principles and addresses outstanding problems of team connectivity, mobility, cognitive load, team awareness, and hands-free interaction in mobile military applications. This research has resulted in the development of a multimodal solution that enhances team coordination by allowing users to synchronize their tasks while keeping an overall awareness of team status and their environment. The set of solutions we’ve developed utilizes optimal interaction techniques implemented and evaluated in related projects; the ultimate goal of this research is to learn how to use technology to provide total situational awareness and team connectivity on the battlefield. This information can be used to aid the research and development of technological solutions for teams that operate in hazardous environments as more advanced resources become available.

This report describes the development of a computer model for the design of a laser seeker optical system. A laser seeker is a device that detects pulsed laser energy. The computer model is configured to design the seeker optics based on the following performance criteria: Sensitivity to laser energy, which can be related to target acquisition range; optical field of view; and seeker optics cross section area. The design is defined by four variables and a set of fixed parameters, and is configured using computer optimization with both a direct search and a random search being used. A superior design is selected from comparison of many sets of variables based on the value of an objective function made up of some of all of the performance criteria listed above and additional penalty factors applied for design constraint violations. The computer model contains design blocks for the detector, the preamplifier, and the optical elements of the seeker. There is also a computer ray trace routine to evaluate optical performance. The model was run with roar different objective functions, and the resulting seeker designs were analyzed. A detail listing of the computer program is contained in Appendix B.

The Small Robot Initiative at the Naval Postgraduate School (NPS) has spent several years in development based on the Foster Miller lemmings platform. This platform, in conjunction with a commercial off-the-shelf (COTS) control architecture, is capable of autonomous, land based waypoint navigation, self orientation, and rudimentary obstacle avoidance. It can receive waypoint information, manual control input, and transmit video and audio information back to a control station via 802.11 wireless communication. The introduction of the WHEGS design, developed at Case Western Reserve University, and a modified version of the COTS control system will provide a platform with greater speed, mobility and versatility. This thesis developed a prototype WHEGS vehicle and integrated the control system with improvements in the navigation routine through the addition of a dead reckoning sensor and calculation function. Although the mechanical design proved to be highly inefficient and unable to propel itself, the control system was successful, allowing integration with a more robust mechanical design from Case Western Reserve University. Follow on development and research will lighten the body through the use of carbon fiber and test the robots ability to maneuver effectively in the surf-zone.

Approved for public release; distribution is unlimited. / This thesis explores the definition of FORCEnet, determines what degree of consensus exists about its concepts and evaluates the Joint Fires Network against FORCEnet principles. The military has been moving toward network based information operations, but struggles to stay current with information technology (IT). IT and knowledge management are not mature disciplines. The services struggle to choose durable standards, processes and systems, and field them across a vast enterprise quickly. Additionally, complex acquisition and configuration processes are incapable of producing interoperable networks on the timescale of IT growth. Though the services and agencies have fielded capable systems in the past, they become legacy if a newer standard is adopted that disenfranchises them. Organizational transformation is required to support flexibility in the Department of Defense. Sea Power 21 is a comprehensive attempt to address the implications of the IT revolution. The legs of the vision are Sea Basing, Sea Shield and Sea Strike. The enabler is FORCEnet, "the operational construct and architectural framework of naval warfare in the information age that integrates Warriors, sensors, networks, command and control, platforms, and weapons into a networked, distributed combat force that is scalable across all levels of conflict from seabed to space and sea to land." / Commander, United States Navy

The purpose of this thesis is to develop a generic control law for unmanned-trail vehicles as they follow a manned lead vehicle. The development of this semi-robotic convoy control law begins with a model of an individual vehicle. Two methods are then explored of coupling these into a model of the column. A relationship between these two methods is derived. The model is then expanded to n vehicles. Utilizing a digital simulation, a three-vehicle convoy is controlled in one degree-of-freedom (DOF) using pole-placement, state-feedback control theory. The analysis shows this to be an unacceptable method of control due to the steady-state error. The 1 DOF model is then controlled with series compensation. Simulations verify that the steady-state error is eliminated. The system is then expanded into a 2 DOF system. Using the same series compensator, a 2 DOF simulation is developed. It is shown that the only additional requirement of the 2 DOF system is that the trail vehicles need to determine their orientation. This is accomplished by first saving the position and velocity profile of the lead vehicle and then developing a search algorithm to find the appropriate information. The simulation verifies that the convoy is controlled within the specifications of the system. / Master of Science

Approved for public release, distribution unlimited / The Anti-Submarine Warfare screen design simulation is a program that provides a model for operations in anti-submarine warfare (ASW). The purpose of the program is to aid ASW commanders, allowing them to configure an ASW screen, including the sonar policy, convoy speed, and the number of ships, to gain insight into how these and other factors beyond their control, such as water conditions, impact ASW effectiveness. It is also designed to be used as a training tool for ASW officers. The program is implemented in Java programming language, using the Multi Agent System (MAS) technique. The simulation interface is a Horizontal Display Center (HDC) which is very similar to a MEKO200 class Frigate Combat Information Center's (CIC) HDC. The program uses Extensible Markup Language (XML) files for reading data for program scenarios; parameters are initialized before each run time begins. The simulation also provides all the output data at the end of run time for analysis purposes. The program user's goal, and the purpose of the program, is to decrease the number of successful attacks against surface vessels by changing the configuration parameters of the ASW screen, to reflect sonar policy, convoy speed or number of ships in the simulation. Ongoing use of the program can provide data needed to anticipate required operational needs in future ASW situations. / Lieutenant Junior Grade, Turkish Navy

Thesis. 1975. M.S.--Massachusetts Institute of Technology. Dept. of Aeronautics and Astronautics. / Bibliography: leaf 112. / by George W. Pfeiffer. / M.S.