Implementation of Terahertz Video SAR Imaging Based on Multi-Core DSP

Terahertz Synthetic Aperture Radar (SAR) is a microwave imaging radar capable of realizing modern high-resolution imaging all-day and all-weather. Terahertz SAR has a large amount of echo data and short pulse accumulation time. It is particularly difficult to realize terahertz video SAR imaging processing. To solve this problem, this paper deeply studies the terahertz SAR imaging algorithm and its hardware acceleration processing, and proposes a terahertz SAR imaging processing system based on multi-core digital signal processor. The system module mainly includes a parameter configuration module, a principle of chirp scaling processing module, an azimuth Sinc interpolation module and a sub-aperture self-focusing module. Firstly, the original echo data is imaged by polar format algorithm, and then the data is divided into several sub-aperture for self-focusing processing based on multiplexing extraction, and the focused image is output. Terahertz measured data show that the proposed imaging processing system can complete the image data processing of $2\mathrm{K} \times 2\mathrm{K}$ in the range and azimuth directions within 0.755s, and 5 high-quality SAR images of $1\mathrm{K} \times 1\mathrm{K}$ are finally output. The imaging rate reaches 5 frames per second which meets the requirements of video imaging.