A concept for the realisation of directional laser Doppler velocimeters (LDV), without having to use opto-electronic modulators like Bragg cells is presented. The concept is based on the use of a diode-pumped fibre laser, emitting at two different wavelengths. The two laser colours are used to generate two interference fringe systems in the measuring volume of the LDV system. The fringe systems...

We present a laser Doppler velocimeter (LDV) in monostatic coaxial arrangement consisting of off-the-shelf telecom-grade components: a single frequency laser (wavelength λ = 1.5 μm) and a high-finesse scanning Fabry-Perot interferometer (sFPI). In contrast to previous 1.5 μm LDV systems based on heterodyne detection, our sFPI-LDV has the advantages of having large remote sensing range not limit...

The many hydrodynamic implications associated with the geomorphological evolution of braided rivers are still not profoundly examined in both experimental and numerical analyses, due to generation three-dimensional turbulence structures around sediment bars. In this research, 3D velocity fields were measured through an acoustic Doppler velocimeter during flume-scale laboratory runs over emergin...

Flow mapping around bridge piers is crucial in estimating scour development potential under different flow conditions. The reliable measurement of turbulence and the estimation Reynolds stress can be achieved on scaled models controlled laboratory experiments using high-frequency Acoustic Doppler Velocimeter Profilers (ADVP) for measurement. aim this paper was to obtain operation parameters an ...