Feasibility Analysis of Laser Doppler Current Probe in the Measurement of Micro-scale Turbulence

Ocean current enhances the diffusion process of momentum, heat, and dissolved matter in the ocean. Ocean turbulence shifts energy from large-scale vortex movements to small-scale vortex movements and ultimately dissipates as heat. Ocean turbulence plays an important role in the process of ocean water exchange and energy transfer, and plays an important role in the oceanic hot salt circulation. Nowadays, there are many kinds of instruments for measuring the velocity of currents, but there are little instruments for measurement of micro-scale turbulence and current velocity with high spatial resolution. Laser Doppler Velocimetry (LDV) has high resolution, non-contact, high accuracy and portability. It plays vital roles in in boundary layer measurement, medical diagnosis, biochemical analysis and liquid-gas real-time measurement. The principle of LDV has been demonstrated and the factors influencing the measurement accuracy of laser Doppler velocimetry are mainly studied. The feasibility of laser Doppler current meter in the measurement of ocean current and micro-scale turbulence has been discussed and the relevant parameters are given through theoretical calculation. The laser Doppler current probe has been proved to be effective equipment to capture the micro-scale subsurface current during a field observation campaign.