Efficient 3-D Imaging Algorithm for Layered Structures Based on Scanning 1-D MIMO Array

Since its unique advantages in the tradeoff between data acquisition rate and hardware cost, the scanning 1-D multiple-input-multiple-output (MIMO) array setup has been widely used in nondestructive testing applications, especially for product quality control on the assembly line. In this article, two fast fully focused algorithms based on scanning 1-D MIMO array are developed for imaging half-space medium structures. Both of the algorithms are derived under the half-space Green's function, and are implemented through fast Fourier transform (FFT) and phase compensation. The only difference between these two algorithms is that the matrix multiplication and nonuniform FFT are, respectively, employed to reconstruct the range profile. Simulation and experimental results verify the effectiveness of the proposed algorithms in computation efficiency and image reconstruction quality.