Analysis Of The Underwater Attitude And The Vibration Signals Of Ocean Turbulence Measurement Instrument Based On Submerged Buoy

The turbulent mixing process in the ocean is the main way of large scale andmesoscale ocean energy switching to small scale and even dissipation, which not onlyhas great influence on momentum, quality and mass transfer, but also plays animportant role in regulating large scale and meso-scale movement such as oceanthermohaline. The study of turbulent mixing phenomenon is of great scientific valuein deepening understanding of ocean internal mechanism and revealing the essence ofocean phenomenon. Long-term, continuous and fixed-point observation is a newdirection in turbulence observation.Analysis of the underwater attitude and the vibration signals of oceanturbulence measurement instrument based on submerged buoy is of great significancein turbulence data processing. This paper addresses the problem that the observationby turbulence measurement instrument can be greatly disturbed, of which theemphasis is on the judgment of usability of the shear signals. In the actual turbulenceobservation, the usage of shear probe is not enough and the cases like vibration andattitude of observation platform should be taken into account; only correcting the dataof shear probe and fusing follow-up data can the effect of observation platform onturbulence observation be eliminated. In order to record the instrument attitude inwater, a attitude sensor is needed to install to synchronously measure acceleration ofX, Y, Z axis-es and angle of heading, angle of pitch and angle of roll.The paper analyses the arguments collected from the attitude sensor. First, studythe pretreatment methods of vibration signals, including calibration transformation ofsample data, elimination of trend term and smoothing sample data, and at the sametime analyze signals in time domain and frequency domain. Then, the author analyzesthe field test data, designs no-vibration sink experiment and near-shore areaexperiment, and proposes methods of evaluating the strength of platform vibrationusing pseudo dissipation rate, thus can determine the feasibility of shear signalscollected. The experiments show that when the differences between dissipation rateand pseudo dissipation rate has two orders of magnitude, vibrating signal has littleinterference to shear signal, which can be ignored. The conclusion offers a quantization method to analyze shear signal with vibrating signal interference, makingsignal analysis more convenient.