Simulation-based undersea warfare assessment

Simulation has long been an important tool in developing tactics and evaluating system performance for the U.S. Navy submarine force. The Object-oriented, Rule-Based Interactive System (ORBIS)-a simulation tool that enables systematic identification of critical submarine capabilities-has been used to provide key insights to APL sponsors over the past 15 years. ORBIS allows the operations research analyst to readily determine "what matters most" to perform the mission at hand effectively. A sample application is a wartime avoidance scenario in which a U.S. submarine detects a threat submarine and maneuvers according to a prescribed rule set to prevent counterdetection. This article provides an overview of ORBIS, a brief description of its history, its application to tactics development and systems assessments, and its underlying passive and active detection models.