人造目标SAR图像实时仿真

根据SAR图像特点,提出了一种利用图形加速的实时SAR仿真方法。方法采用散射中心模型,基于高频预估理论,用物理光学(PO)法与增量长度绕射系数(ILDC)法计算目标表面散射场强度分布,将强度值累积映射到SAR图像的分辨单元内,与成像系统传输函数卷积,获得近似仿真结果。散射、映射与卷积运算均借助图形加速,仿真可在数秒内完成。仿真结果与真实图像相比具有良好的视觉相似度。为算法测试而搭建的仿真平台OpenSARSim被作为开源项目,其所采用的部分技术可以应用于其它仿真领域。

Real-time Simulation of SAR Image of Artificial Target

Based on the characteristic of SAR image, a real-time simulation method assisted was put forward by graphics ac-celerator. The method adopted the scattering center model based on the high frequency predict method. The scattered field distribution was computed using Physical Optics (PO) method and Incremental length diffraction coefficients (ILDC) method and then maps scattering intensity into azimuth-range resolution cell accumulatively, and the mapping result was convoluted with the transmission function of imaging system. The computation of scattered field, mapping transformation and convolu-tion was speeded up by graphics accelerator. The simulation could be finished in seconds. To compare with the real image, the simulation result has high visual similarity. The simulation platform OpenSARSim which was built for algorithmic test was treated as open source project. Some techniques adapted by the project could be applied in other simulation domain.