Four-dimensional (4-D) Oceanographic Instrumentation

In Phase 2, CCD proposes to build and test directional wave buoy prototypes that are smaller than a soda can and could cost less than $1,000 in production. The heart of this new directional micro-buoy is a Tiny Guidance Engine (TGE) developed originally for smart munitions. In less than a cubic inch, TGE measures all 6 degrees of freedom inertially, 3 axes magnetically, pressure, and temperature. A low cost RTK enabled GPS receiver measures position, velocity, and time. Optionally, if a fixed GPS receiver location is available, absolute buoy position is reported to centimeter accuracy. The microcontroller is optimized for extremely low power consumption so a small solar cell allows indefinite operational life. Inertial data provides a backup for GPS measurements and helps coast through possible outages due to temporary submergence. Wave and other data will be compressed and then transmitted to Argos, Orbcomm or Iridium satellites or to local receivers, depending on the mission. Additional sensors (depth, salinity, humidity, turbidity, conductivity etc.) can be added as desired. This microbuoy can be moored on ‘fishing line’, or airdropped and left to drift. In the latter case, the buoy also functions as a dropsonde while descending as its trajectory defines the wind profile.