Synthetic Aperture Radar (SAR) Imaging of Complex Scenes Considering Near-Field Scattering Characteristics

摘要

Synthetic Aperture Radar (SAR) imaging from low altitude aerial vehicles has been gaining much importance togetherrnwith the widespread use of Unmanned Aerial Vehicles (UAVs). Relatively shorter distances between the mentionedrnvehicles and imaged scenes require the consideration of near-field scattering phenomenon. In this paper, authors hasrnfocused on the design of a SAR simulator for low altitude vehicles that takes the stated phenomenon into account. Therninputs of the simulator are a 3-D complex scene consisting of artificial targets and natural environment constructedrnby triangular surface meshes and parameters of the SAR system. Scatterer reflectivities are evaluated by utilizing thernnear-field Physical Optics (PO) method and SAR raw data is generated in time domain. Finally, the simulator processesrnthe raw data and constructs the SAR images via Doppler Beam Sharpening (DBS) algorithm.