A variety of different measurement techniques is employed at the BSH. During
ship based experiments electronic devices are used which can be lowered through
the water column on wires or can be towed behind a moving ship. Moorings
and platforms have the advantage that measurements can be performed over longer
time periods at a fixed position. Usually, the data are stored within the instrument
and will be down-loaded after the recovery of the instruments. Deep drifters
also operate in an internal registration mode. They are not fixed to one position
but drift passively through the oceans carried along by the ocean currents.
Satellites and air planes allow a remote sensing of the ocean and deliver information
on the physical state of the sea surface.