Wireless Acoustic Buoy Array Multi-Targets Tracking And Positioning System

Acoustic positioning system has wide application in Ocean Scientific field. However, existing systems have disadvantages of bulkiness, perplexing operation, limited position range and low precision, resulting in their incompetence of satisfying many application needs. With the development of Acoustics and Signal Processing theory, as well as that of DSP and DGPS technology, it is possible for us to develop more advanced positioning systems.The main work of this thesis includes: system level design and implementta-tion of an Underwater Multiple Targets Tracking (UMTT) system, use of the embedded DGPS receiver in buoy, migration of wireless communication system on ocean, and performance verification by experiments.System architecture design is crucial to a system's performance. Our system is composed of display and control subsystem on boat, relay station, and buoys. Among others, buoy-style structure is one of its innovations, which enables it to track and position targets in wide range with high precision. This thesis introduces the design mode of the system, acoustic signal detection and estimation methods, how to position and solve, etc. Others discussed in the thesis include software and hardware realization of buoy electrical platform and base station synthesizer, and module design of controlling application.According to position principle, it is necessary to get buoys' location besides targets' acoustic information. Fortunately, DGPS has made such problem easy to be solved. With DGPS embedded in buoy electrical platform, accurate location of buoy can be dynamically acquired. In addition, nodes in the system need be synchronized periodically to properly work, where DGPS also plays an important role. The 1PPS (one pulse per second) signal output from DGPS provides an easy way to accurately time using an ordinary clock. Its use and synchronizationmethods are presented in the thesis.Measurement data of buoys is collected for master computer, where target positions are obtained by synthesizing data and resolving equations. Data exchange between buoys and computer comes true with the help of wireless microwave spread spectrum communication system, which is a wireless LAN comprising buoys, relay and base station synthesizer and utilizing 2.4 GHz band with bit rate up to 1Mbps. As we know, ssuch wireless digital microwave communication is seldom put into action on ocean, and then offers a challenge for us. Next, the thesis illustrates the feature of transceiver and how to communicate, and designs communication protocol on the basis of practical working environment. Communication acceptance range is one of the important issues to be considered during design. Through theory analysis, simulation and experiment on ocean, reliable communication can be achieved as distance between base station and buoy increasing up to 15 kilometer, which guarantees the system's tracking range.Lastly, this thesis gives detail information about experiments both on lake and on ocean, in which many high performance of the system has fully embodied.