SAR Imaging for Low-altitude Subsonic Unmanned Aerial Platform with Fixed Forward Inclination Angle Scenarios Based on Fast Factorized Back Projection

A Synthetic Aperture Radar (SAR) imaging method based on the fast factorised backward projection (FFBP) algorithm is proposed for Low-altitude subsonic unmanned aerial platform detecting scenarios in forward-skewed regions. Firstly, given the low-altitude subsonic unmanned aerial platform flying with a fixed forward inclination angle, the relationship between the range resolution and azimuth resolution is established under the spotlight mode, and the parameters required for imaging are solved by the proposed Newton method. Secondly, the FFBP algorithm decomposes the whole imaging region into multiple subregions, and local backward projection is performed in each subregion, which greatly reduces the computational complexity of the traditional backward projection algorithm. Finally, the local projection results of each subregion are merged to form a high-quality image. Experiments show that this method can effectively deal with flight scenarios with fixed forward inclination angle, providing an efficient and robust solution for the low-altitude subsonic unmanned aerial platform SAR imaging.