The Expendable Bathythermograph (XBT) has been used by
oceanographers for many years to obtain information on the temperature structure
of the ocean to depths of up to 1500 meters. The XBT, shown in Figure 1, is a
probe which is dropped from a ship and measures the temperature as it falls
through the water. Two very small wires transmit the temperature data to the
ship where it is recorded for later analysis. The probe is designed to fall at a
constant rate, so that the depth of the probe can be inferred from the time
since it was launched. By plotting temperature as a function of depth, the
scientists can get a picture of the temperature profile of the water.
On many projects it is necessary to deploy
XBTs on a 24 hour schedule as the ship steams along its course. Since a trained
operator is needed to operate the system, it was necessary to send two people so
that operations could be conducted around the clock. To reduce the workload,
AOML has designed and is now testing an automated XBT
launcher that will allow this work to be conducted by only one person.
Eventually, it is hoped, the ship's crew will be able to operate the system and
no operators will have to accompany the system.
A photograph of the XBT Autolauncher is shown in
Figure 2. Up to
six probes can be preloaded and then deployed at predetermined launch times or
positions.
