Measuring reflection coefficients of underwater sound material at oblique incidence using broadband acoustic holography

A method using broadband acoustic holography has been put forward to determining the reflection coefficients at arbitrary angles of incidence and compared with mono-frequent acoustic holography. The selection principle about every parameter has been deduced by numerical experiments on an aluminum board. Under an average error level of 10%, the radius of holographic plane should be greater than two times of the maximal wavelength, and the interval of two space samples has better to be less than one-third of the minimal wavelength, the height of the first measurement plane should at least be less than two-thirds of the minimal wavelength, the vertical distance between the two measurement planes should at least be less than half of the minimal wavelength, the height of sound source is proposed to be in between one-fifth of the maximal wavelength and four times of the minimal wavelength.