Fast FactorizedBackprojection Algorithm for Near-Range Handheld Microwave Imaging

The development of imaging algorithms for near-range handheld synthetic aperture radar (SAR) systems has attracted significant attention due to the remarkable performance of portable millimeter-wave (MMW) imaging devices across diverse application fields. This paper proposes a novel fast factorized backprojection algorithm for handheld SAR (HHFFBPA), which extends the factorization techniques traditionally used in far-field SAR imaging. The localized spectral characteristics of the radar images in handheld systems are rigorously analyzed, and analytical spectrum compression techniques are derived to facilitate efficient subimage downsampling. Comprehensive numerical simulations demonstrate that the proposed HHFFBPA achieves both high computational efficiency and precise 3-D imaging for handheld SAR systems.