A method for testing phased array acoustic Doppler velocity log on land

As Phased Array acoustic Doppler Velocity Log (PADVL) is widely used on oceanographic vessels and other platforms, it is necessary to provide a systematic examination on land. A Phased Coupling Array Method (PCAM) is proposed in this paper. When one Phased Array (defined as PA I) is placed face to face with array of PADVL (defined as PA II), simulating echo signals can be coupled from PA I into PA II. By the comparison between the predetermined parameters of the simulating echo signals and the measuring results from PADVL, the status of PADVL can be confirmed and a more reliable, comprehensive and convenient examination on land can be realized. Model of the signal interaction between the two arrays is established. And two main sources of error, i.e. misalignment angles and eccentric error are examined. The results show that: misalignment angles have small influence on the coupling performance; ideal coupling performance can be received when misalignment angle |β|⩽3°|β|⩽3° , |γ|⩽3°|γ|⩽3°, |α|⩽6°|α|⩽6°, and eccentric error ΔxΔx, Δy⩽2λΔy⩽2λ. The measured results from the prototype are consistent with the simulation, which further verifies the proposed method.