An integrated acoustic remote sensing and communications system for tidal front mapping

A fundamental need exists in ocean science for accurate mapping of spatial and temporal variability of oceanographic parameters. The Autonomous Oceanographic Sampling Network (AOSN) concept offers this capability by combining an acoustic remote sensing and communication network with a fleet of AUVs equipped with sensors. In June of 1996, an AOSN was deployed in Hare Strait, British Columbia to monitor an active tidal front. Each system includes a tomography source, a communication source, a sixteen channel hydrophone array for receiving acoustic tomography and communications, and an array navigation system for monitoring hydrophone positions. The main electronics package on each mooring is comprised of a PC, DSPs, and analog-to-digital converter boards. Each mooring in the network is controlled in real time via a wireless Ethernet link to a base station located approximately 16 km away on Vancouver Island. Here, all data are logged and analyzed as the experiment is dynamically configured to monitor the evolving front. Some of the unique aspects of both the hardware and software system designs as well as preliminary results from the experiment are described.