Architecture Exploration of a Backprojection Algorithm for Real-Time Video SAR

• DOI: 10.3390/s21248258
• Publication Date: 2021-12-10T13:17:58Z
• Authors: Seokwon Lee; Inmo Ban; Myeongjin Lee; Yunho Jung; Wookyung Lee
• Keywords: backprojection; Chemical technology; synthetic aperture radar; SAR; video SAR; backprojection; sub-aperture processing; overlapped aperture mode; TP1-1185; 02 engineering and technology; sub-aperture processing; Article; overlapped aperture mode; 0202 electrical engineering, electronic engineering, information engineering; video SAR; synthetic aperture radar; SAR

This paper explores novel architectures for fast backprojection based video synthetic aperture radar (BP-VISAR) with multiple GPUs. The video SAR frame rate is analyzed for non-overlapped and overlapped aperture modes. For the parallelization of the backprojection process, a processing data unit is defined as the phase history data or range profile data from partial synthetic-apertures divided from the full resolution target data. Considering whether full-aperture processing is performed and range compression or backprojection are parallelized on a GPU basis, we propose six distinct architectures, each having a single-stream pipeline with a single GPU. The performance of these architectures is evaluated in both non-overlapped and overlapped modes. The efficiency of the BP-VISAR architecture with sub-aperture processing in the overlapped mode is accelerated further by filling the processing gap from the idling GPU resources with multi-stream based backprojection on multiple GPUs. The frame rate of the proposed BP-VISAR architecture with sub-aperture processing is scalable with the number of GPU devices for large pixel resolution. It can generate 4096 × 4096 video SAR frames of 0.5 m cross-range resolution in 23.0 Hz on a single GPU and 73.5 Hz on quad GPUs.