Lateral detecting ability of three dimensional underground imaging using electromagnetic induction type sound source

A three dimensional imaging method using electromagnetic induction type sound source and amplitude correlation synthesis processing method was proposed in our previous work. Considering the directivity of the sound source and the nonlinearity of the processing method, this paper discusses the lateral detecting ability of the method by both numerical simulation and experimental testing. Three objects at identical depth are measured with varying lateral positions relating to the sound source and receiver array. The results show that the lateral detecting ability is determined mainly by the directivity of the sound source and the efficient detecting area is about 35∘ inside the spread angle of the sound source.