Perimeter Security and Intruder Detection Using Gravity Gradiometry: A Feasibility Study

Changes in the mass distribution around some point on the Earth’s surface induce corresponding changes to the magnitude and direction of the gravity vector at that location. The nine-tensor derivative of the gravity vector, or gravity gradient, is sensitive to very small changes in the gravity vector. With some assumptions, continuous measurement of the gravity gradient using a gravity gradiometer (GGI) is used to determine the location of a mass change in the local area near the instrument. This investigation sought to determine the effectiveness, operating characteristics, and limitations of a physical perimeter security system that uses an array of GGIs to detect and locate a human intruder. Results are obtained via computer simulations utilizing the closed form solution for calculating a gravity gradient given an object’s size and mass, as well as industry-predicted future GGI performance characteristics

Speed Through Flexibility: Shortening the Acquisition Timeline of U.S. Defense Capabilities Using Flexible Systems

Military procurement projects face a fundamental dilemma: systems designed and built today must serve the needs of the future, but future needs cannot be reliably forecasted. This reality drives the U.S. defense acquisition system, which creates and maintains defense capabilities in a constantly changing world. There is consensus that in today’s dynamic environment the cumbersome acquisition process operates too slowly to field needed capabilities on a relevant timeline. Despite many proposals to speed the process through reform, significant changes have remained elusive due to the complex stakeholder landscape. Therefore, acquisition techniques that can increase the speed of fielding required capabilities within the acquisition process that exists today are especially valuable. This thesis advocates for faster capability delivery by deliberately designing systems to be flexible so that new capabilities can be created through system modification rather than new system creation. Although evidence suggests that flexible systems often provide more value than inflexible ones due to their ability to adapt to unforeseen conditions, flexibility remains an uncommon attribute of defense systems due to the lack of established procedure within the acquisition process on how to create flexible systems. A case study of the U.S. Air Force Ground Based Strategic Deterrent (GBSD) weapon system is used to demonstrate an approach for creating flexible defense systems. Interviews with key personnel and program documentation are used to explain how the GBSD program worked within the constraints of the DoD acquisition system to implement a holistic flexibility strategy based on open system architecture, design margin in key areas, and architectural diversity, thereby creating the conditions for system flexibility. Flexibility in the GBSD program has contributed to schedule certainty during development and will provide a way to respond more quickly to new threats and take advantage of new technology when the system becomes operational. This thesis finds that it is possible to acquire flexible defense systems today and provides recommendations to foster the acquisition of flexible defense systems.S.M