Wake Up and Ascend:
Firstly Sensor Buoy wakes up by Scheduler and sends the wake-up command to underwater winch (SEASAW-2) via acoustic remote, when the scheduled time comes. And Buoy turns on the installed sensors. After aging time (User setting parameter), Buoy starts data-logging with 1Hz. When SEASAW-2 receives Buoy’s wake-up command, SEASAW-2 sends the repeat response to Buoy and starts its motor operation with rope-out direction.
When Buoy reaches at 2m depth, Buoy starts searching for communication satellites. If Buoy finds them, it is judged that the Buoy arrives at the surface. Then Buoy transmits the stop command to SEASAW-2.
Descend and Sleep:
After few minutes, Buoy sends the down-command to SEASAW-2. After the receipt of command each other, SEASAW-2 starts reeling rope and Buoy becomes stand-by mode in order to save the battery. Finally SEASAW-2 docks Buoy with its latch unit, and SEASAW-2 sends the stop command to Buoy. They confirm their docking and sleeps by the next schedule.
Following data are acquired by the above sequence once a day for 3 months without any maintenance. They are useful goods for environmentl research.