Reserch Of Echo Data Acquisition And Processing Based On Bistatic SAR

Bistatic Synthetic Aperture Radar(BiSAR)has the advantages of flexible configuration,good anti-interference,and strong survivability.It can be applied to military reconnaissance,terrain mapping and other fields.However,due to the complex structure of the system,It is difficult to achieve accurate capture and high-speed acquisition of radar echo pulses.Due to the large computational complexity and high computational complexity,the imaging processing efficiency is low.In this thesis,aiming at the structural characteristics of bistatic SAR,an echo acquisition scheme based on NI PMA-1115 high-speed acquisition system is designed.Aiming at the characteristics of large data size and complex calculation,a parallel processing architecture based on general-purpose GPU is designed.And achieved the acquisition subsystem and processing subsystem interconnection,formed a complete data acquisition-processing system.The main contents of this thesis as follows:1.Aiming at the specific spatial geometric configuration of bistatic SAR system,the law of echo is analyzed and the echo model is derived.Based on this,the BP imaging algorithm is studied and the computational load of the algorithm is analyzed.At the same time,the autofocus principle and implementation method are studied,which provides a theoretical basis for the design of the data acquisition scheme and the hardware implementation of imaging processing.2.Aiming at the structure characteristics of the bistatic SAR and the working mode of the synchronous system,a high-efficiency,stable echo acquisition and storage scheme is designed,including a synchronous pulse trigger control scheme,and data storage scheme and so on.A Lab VIEW-based display control software is developed,accurate capture and high-speed acquisition of echo pulses of bistatic SAR are realized.3.In view of the large computational complexity and high computational complexity in the bistatic SAR system,the principle of GPU hardware architecture and CUDA parallel programming was studied,and a bistatic SAR echo high-speed parallel processing architecture based on GPU was established,a CUDA parallel program based on BP imaging algorithm is designed and optimized,improving the speed of bistatic SAR imaging processing.4.The data transmission program based on TCP protocol was developed,the problem of data separation between the acquisition subsystem and the imaging processing subsystem was solved,real-time transmission of echo data was realized,and a complete data acquisition-processing system was constructed.The above research contents have been verified through simulation and experiments.The acquisition subsystem can accurately and efficiently collect bistatic SAR echo data.The imaging processing subsystem can realize real-time imaging processing of bistatic SAR under a certain data scale.