Development of integrated, autonomous, modem-based underwater observatories

The U.S. Navy requires advances in environmental and threat sensing over extended areas and over time, or so-called 4-Dimensional Sensing. The goal is to provide more capable, better integrated, and less expensive sensor systems for a variety of applications, including measurement of physical characteristics of the ocean, threat detection, and timely transmission of the data to end users. The dissemination of data collected from undersea systems historically has been accomplished via cable and/or by KF telemetry. In many cases the available (limited) signal processing capability has required the transmission of raw or only slightly processed data to the end user. Because of limited telemetry bandwidths, only a few sensors could therefore be active at any one time. Due to recent major advances in DSP technology, it is now possible to develop systems of sensors with substantial organic computing power which permits in situ data processing and data fusion. Because of recent major advances in undersea wireless acoustic communications, it is possible to deploy networks of such sensor systems covering large ocean areas, from very shallow water to the deepest oceans. The acoustic telemetry required for autonomous, networked sensing is now largely available, but the "plug-and-play" integration of disparate sensor systems is just beginning to be addressed. We describe the infrastructure under development at Benthos in support of autonomous underwater observatories.