Development of new technologies for the high variability phenomena data acquisition in MFSTEP_VOS project.

Physical and biological processes of the marine ecosystem have a high spatial and temporal variability, whose study is possible only through high resolution and synoptic observations. For this reason a new sliding vehicle (SAVE) was designed, in order to collect physical and optical profiles in the upper 200 m of the water column. SAVE slides along a cable between the surface and a depressor, that is towed at a fixed depth, and is composed of an underwater unit, an on board unit and a data transmission system. A prototype was realised in the framework of the EC funded project MFSTEP. Many tests have been performed by using the R/V 'Luigi Sanzo' of the CNR IAMC -- Section of Messina: o SAVE depressor navigational behaviour o Pitch, roll and depth stability o Data acquisition from trim control. The depressor was manufactured from PVC and was deployed at different depths to test the behaviour in the water. A cylinder pressure vessel was installed on the SAVE depressor containing a miniature pressure transducer and a biaxial inclinometer sensor. A test version of the sliding vehicle was made in PVC, containing a CTD probe, fluorimeter and PAR sensors. SAVE was connected to the depressor cable through a sliding system of teflon, and acquired physical-chemical and biological parameters in the water from surface to the depressor depth.