A super-resolution near-field scattering centers extraction method for spherical wavefront curvature compensation

While a radar target is illuminated under the condition of spherical wave, two-dimensional ISAR image can be obtained in near field, and the wavefront curvature must be compensated. A novel two-dimensional mathematical model is set up, and a 2D- ESPRIT super-resolution algorithm based on matrix pencil is applied to estimate the accurate locations of the scattering centers in near field. Numerical simulations are conducted in different distances as well as with different SNRs. It is proved that the method can revise the spherical wavefront curvature with a high accuracy. Finally, near field ISAR imaging experiments were done outdoor, and raw data were processed with this super-resolution method, which verify that 2D-ESPRIT algorithm based on matrix pencil can compensate the spherical wavefront curvature effectively in near field.