Problem
One of the most significant expenses of an oceanography project is the cost of operating a ship, first to place the instruments and then to return and recover them and the all important data. Ship operating costs are many thousands of dollars per day. Much of AO's oceanographic instrumentation efforts have been directed at producing low cost instruments. One of the consequences is that it can be much less expensive to abandon instruments after the project is complete than to go out and retrieve them - if there is a way to recover the data.
Solution
We modified our inexpensive Vector Averaging Current Meter mechanism to attach a water-tight Benthos sphere to the top. Inside the sphere was a control processor and an Argos satellite transmitter. The Argos satellite system is a convenient way for researchers to receive data from instruments in remote locations.
We adapted our Inductive Communications Interface to allow the processor in the VACM to talk to the processor in the sphere to transfer data. The sphere accumulated data during the life of the project. The Expendable VACM was anchored to the bottom through our 9522 Meltline Release. After the project period was over the Meltline Release cut the anchor line and the VACM assembly floated to the surface. When the transmitter processor sensed the sphere to be on the surface it began transmitting the accumulated data to the Argos satellite orbiting overhead.
Results
The Expendable VACMs cost far less that the operating cost of a ship for one day. They were especially cost efficient on projects in remote oceans that required long deployments. Best of all, the researchers received their data on their office computers over the Internet, without having to endure another long sea voyage.
