Homogenization of non-uniform data grid in millimeter scanning imaging system by time shifting

摘要

In our millimeter wave scanning imaging system, two-dimensional non-uniform data grid as shown in Fig. 1 is generated. Consequently, fast Fourier transform (FFT) for uniform data grid as shown in Fig. 2 cannot be immediately applied. In general, there are two ways to compute discrete Fourier transform (DFT) for non-uniform data grid, non-uniform FFT (NUFFT) and interpolation. However, computational efficiency for both of them is not satisfactory.