Inverse Synthetic Aperture Macroscopic Fourier Ptychographic Imaging of Moving Targets

ABSTRACT High‐resolution imaging of distant, dynamic targets is fundamentally limited by finite‐aperture diffraction. Unlike radar, optical detectors record only intensity and lack the temporal resolution for direct phase measurement, hindering straightforward extension of synthetic aperture techniques to the optical domain. While Macroscopic Fourier ptychography (FP) offers a promising computational alternative, its reliance on mechanical scanning or engineered illumination restricts its use to cooperative, static scenes. In this paper, we present Inverse Synthetic Aperture Macroscopic Fourier ptychography (ISAMFP), which, to the best of our knowledge, is the first practical realization of inverse synthetic aperture imaging for diffusely reflecting targets within the Fourier ptychography framework. By transforming the natural target motion from a detrimental factor into an effective source of angular diversity, ISAMFP eliminates the need for mechanical scanning or illumination modulation and achieves resolution enhancement far beyond the aperture limit using intensity‐only measurements. Experimental validations on USAF resolution targets, unmanned aerial vehicles, and complex multi‐target scenes highlight both the robustness and versatility of ISAMFP, establishing it as a powerful tool for non‐interferometric synthetic aperture imaging of moving, non‐cooperative targets, with broad implications for surveillance, defense, and remote sensing.