Design And Implementation Of Video SAR Imaging Processing System Based On FPGA

Synthetic aperture radar is an important milestone in the development of radar technology.It not only has the characteristics of all-weather,all-time,and long-distance,but also can analyze the real scene based on the echo characteristics.However,the word "image" is often accompanied by a higher amount of data.The higher data volume also puts higher requirements on the processing capability of the radar real-time imaging system.Thesis takes the design and implementation of the real-time imaging system in the terahertz SAR system as the main research direction,and realizes a set of SAR real-time imaging system based on the ZYNQ-7020 platform and based on RD and PFA imaging algorithms.The main work content is as follows :1.Research the processing methods of RD and PFA imaging algorithms under the De-chirped operation,some adjustments were made to the processing procedures of the two algorithms after weighing the complexity of the algorithm and the imaging quality.And aiming at the wavenumber domain correction step in the PFA imaging algorithm,a low-complexity interpolation matrix processing scheme is proposed to replace the traditional two-dimensional nonlinear interpolation process.2.Analyze the signal transmission and processing flow,through the parameters of the terahertz SAR and the design indicators of the imaging system.Then,allocate tasks for the PL side and PS side of the ZYNQ platform Reasonably,study the communication mechanism and data caching method between the modules,and propose a video stream based on adaptive amplitude compression + pseudo-color space mapping for imaging needs.3.The PL side mainly completes the interaction with the DDR buffer area,the bigendian byte order to the little-endian byte order of the data,FFT/IFFT,skew processing,modulo operation,pseudo-color mapping,data stream to video stream and then transfer TMDS signal,which aims to improve the data processing speed through the idea of pipeline design.4.The PS side uses dual-core ARM as the main part,completes Ethernet reception,wavenumber domain correction,data matrix transposition and spectrum shift,signal amplitude adaptive compression,and the design of the driver program for the PL part of the module,and proposes a set of simple Module scheduling scheme to replace the processing system with higher complexity.5.Connect the system to the terahertz SAR,and perform the joint debugging test of the whole system.The correctness of the designed system is verified by comparing the processing results of the RD and PFA imaging algorithms with the imaging results of MATLAB in the turntable mode and the strip mode,and the real-time system-level imaging frame number ensures that the system meets the design requirements.