An Overview of Next-Generation Underwater Target Detection and Tracking: An Integrated Underwater Architecture <s> II. UNMANNED UNDERWATER VEHICLES FOR TARGET DETECTION AND TRACKING <s> The naval warfare environment is rapidly changing. ::: The U.S. Navy is adapting by continuing its blue-water dominance ::: while simultaneously building brown-water capabilities. Unmanned ::: systems, such as unmanned airborne drones, are proving pivotal in ::: facing new battlefield challenges. Unmanned underwater vehicles ::: (UUVs) are emerging as the Navy's seaborne equivalent of the Air ::: Force's drones. Representing a low-end disruptive technology ::: relative to traditional shipborne operations, UUVs are becoming ::: capable of taking on increasingly complex roles, tipping the scales ::: of battlefield entropy. They improve mission outcomes and operate ::: for a fraction of the cost of traditional operations. Furthermore, ::: long-term underwater power sources at currently under development ::: at MIT will extend UUV range and operational endurance by an order ::: of magnitude. Installing these systems will not only allow UUVs to ::: complete new, previously impossible missions, but will also ::: radically decrease costs. I explore the financial and strategic ::: implications of UUVs and long-term underwater power sources to the ::: Navy and its future operations. By examining current naval ::: operations and the ways in which UUVs could complement or replace ::: divers and ships, I identify ways to use UUV technology to reduce ::: risk to human life, decrease costs, and leverage the technology ::: learning curve. I conclude that significant cost savings are ::: immediately available with the widespread use of UUVs, and current ::: research investment levels are inadequate in comparison with the ::: risks and rewards of UUV programs. <s> BIB001 </s> An Overview of Next-Generation Underwater Target Detection and Tracking: An Integrated Underwater Architecture <s> II. UNMANNED UNDERWATER VEHICLES FOR TARGET DETECTION AND TRACKING <s> Underwater surveillance has traditionally been carried out by means of surface and undersea manned vessels equipped with advanced sensor systems. This approach is often costly and manpower intensive. Marine robotics is an emerging technological area that enables the development of advanced networks for underwater surveillance applications. In contrast with the use of standard assets, these advanced networks are typically composed of small, low-power, and possibly mobile robots, which have limited endurance, processing and wireless communication capabilities. When deployed in a region of interest, these robots can cooperatively form an intelligent network achieving high performance with significant features of scalability, adaptability, robustness, persistence and reliability. Such networks of robots can be the enabling technology for a wide range of applications in the maritime domain. However, they also introduce new challenges for underwater distributed sensing, data processing and analysis, autonomy and communications. The main thrust of this study is to review the underwater surveillance scenario within a framework of four research areas: (i) underwater robotics, (ii) acoustic signal processing, (iii) tracking and distributed information fusion, and (iv) underwater communications networks. Progress in each of these areas as well as future challenges is presented. <s> BIB002 </s> An Overview of Next-Generation Underwater Target Detection and Tracking: An Integrated Underwater Architecture <s> II. UNMANNED UNDERWATER VEHICLES FOR TARGET DETECTION AND TRACKING <s> This paper presents a technique by which a low-cost, minimally-equipped unmanned underwater vehicle (UUV) can localize itself while submerged using acoustic emissions of transiting sources of opportunity (SOOs). The technique provides a bounded estimate of the UUV position and is intended to supplement the on-board Inertial Navigation System (INS). The technique exploits two physical phenomena, the Doppler effect and the waveguide invariant, which are common to received acoustic signals from sources of opportunity, and is termed waveguide invariant / Doppler-based localization (WI-DBL). The Doppler effect is used to obtain source bearing estimates through a least squares-based technique, and the waveguide invariant is applied to the channel fading pattern to obtain range estimates. There is no requirement for the source track to exhibit the closest point of approach (CPA), nor is there a requirement of prior knowledge of source frequencies or maneuvering of the receiver. Simulated results are presented, which are based on data obtained from a cargo ship transiting a shallow water region during the Noise'09 experiment. <s> BIB003 </s> An Overview of Next-Generation Underwater Target Detection and Tracking: An Integrated Underwater Architecture <s> II. UNMANNED UNDERWATER VEHICLES FOR TARGET DETECTION AND TRACKING <s> Focusing on coordination and consensus, this paper, addresses a control problem for a group of unmanned underwater vehicles (UUVs) by tracking a maneuvering target with varying velocity and time delays. To realize coordinated target tracking, consensus control of multiple UUVs requires neighboring UUV state information, detected target state information, and estimated target acceleration information. At least one UUV is assumed to be capable of obtaining information about the target, and the communication topology graph of the vehicle is assumed to be undirected connected. We consider the convergence analysis of this multi-UUV system for two conditions: information interaction between the target and an UUV with time delays and information interaction between the target and an UUV without time delays. Sufficient conditions for the uniform ultimate boundedness of the tracking errors and estimation errors are obtained by utilizing a Lyapnov-Krasovskii functional. Two simulations are presented to demonstrate the effectiveness of the proposed method. <s> BIB004 </s> An Overview of Next-Generation Underwater Target Detection and Tracking: An Integrated Underwater Architecture <s> II. UNMANNED UNDERWATER VEHICLES FOR TARGET DETECTION AND TRACKING <s> In this paper, we describe an unmanned underwater vehicle (UUV) behavior designed to track nearby vessels using bearing-only measurements obtained from a rigidly mounted planar hydrophone array—one that was originally designed for active sonar use but is repurposed for passive sonar use. Upon detecting a target, a maneuver is executed to resolve the port/starboard bearing ambiguity. The maneuver is heuristically designed with the aim of reducing the effects of end-fire, self-noise during maneuvers, and other noise/spurious measurements on the bearing ambiguity decision. After resolving the bearing ambiguity, the vehicle continuously adjusts its heading to track the target by keeping it broadside to the array. The performance of this behavior, as well as that of the passive sonar itself, is evaluated through field trials in the approaches to Boston Harbor using a Bluefin-21 UUV. In total, 19 successful behavior tests are described where the UUV resolves the bearing ambiguity and tracks either a static source emitting a predefined waveform or the platform noise of a medium-sized catamaran underway. <s> BIB005
Unmanned underwater vehicles (UUVs) are becoming part of underwater surveillance systems due to their persistency of monitoring a specific area with low costs BIB002 . UUVs are evolving as Navy's seaborne which is equivalent to Air Forces' drones BIB001 . A target tracking scheme using UUV to resolve bearing ambiguity for unique passive sonar system by executing maneuver after target detection is proposed in BIB005 . The system was unique because the arrays were originally designed for active sonar system and was repurposed for passive sonar system. Maneuver was executed due to the incapability of passive sonar systems to distinguish between port and starboard sides of arrays. Due to repurpose system, the performance was not good, but the system has advantage of target tracking with low cost due to not demanding any additional sensors. A coordinated scheme to track a maneuvering target by multiple UUVs with variable velocity and time delays is proposed in BIB004 . To achieve the goal, the information of neighboring UUV state, target state, and target acceleration is required. The scheme does not assure stability due to not considering time-varying factors of switching topology. The self-localization of UUV with a bounded estimation of its position based on signals from sources of opportunity (SOOs) is presented in BIB003 . The technique considers waveguide invariant and Doppler Effect 98842 VOLUME BIB005 2019 and is known as waveguide invariant Doppler-based localization (WI-DBL) technique. The simulation results show that position estimation is reliable with less error in shallow water whereas deep water environment has some limitations. Three types of UUVs are equivalent to the drones of the sea: AUVs, remotely operated vehicles (ROVs), and gliders BIB001 .