| This dissertation describes the development of an acoustic data storage tag for long-range fish tracking in the ocean. The core of the tag is a custom integrated circuit fabricated in 0.5μm CMOS. Device geopositioning is achieved with an on-board hydrophone listening for signals from several moored acoustic sources. Environmental data in the form of temperature and pressure is periodically sampled. All acquired data is stored locally. The tag's sampling protocol is completely programmable via a PC interface. This interface also allows sensor calibration and retrieval of data at the end of the tag's mission. Sensors, batteries, nonvolatile RAM and a quartz crystal are the only components external to the custom integrated circuit, enabling a smaller and more power-efficient device.; The tag circuitry has been thoroughly simulated in MATLAB and HSPICE, and prototype integrated circuits have been fabricated. Tests have proven the feasibility of the employed tracking method as well as proper operation of the remainder of the tag electronics. |
