SAR扩展场景原始数据混合域仿真方法

Raw Data Simulation of SAR Extended Scenes in Hybrid Domain

针对理想航迹和真实航迹情况下的合成孔径雷达(Syn thetic aperture radar,SAR)扩展场景目标原始数据仿真,给出了两种混合域仿真方法。在理想航迹情况下,根据原始数据二维频谱的精确解析式,给出了一种距离向时域方位向频域的混合域仿真方法,除驻定相位原理引入的误差外,该方法在推导过程中没有做任何近似处理。在真实航迹情况下,给出了包含任意航迹偏移的SAR距离模型,通过对距离模型的近似处理,提出了一种距离向频域方位向时域的仿真方法。给出了具体的仿真实验,在理想航迹下与常规时域方法比较,给出了原始数据相位比较曲线。在真实航迹下分析了距离模型近似误差,并给出了原始数据运动补偿前后的成像结果。仿真结果证明了两种方法的准确性和高效性。

To simulate synthetic aperture radar（SAR） raw data of extended scenes along ideal trajectory and actual trajectory,two simulation approaches in the hybrid domain are proposed.Firstly,a precise two-dimensional Fourier domain formulation of raw data is presented in the case of ideal trajectory.Based on the formulation,a simulation scheme for the processing in range time domain and azimuth Fourier domain is obtained.The scheme has no approximation suggestion except the error caused by the phase-stationary principle.Then,a novel SAR distance model including arbitrary trajectory deviations is introduced under the condition of the actual trajectory.With the approximation of the distance model,a simulation scheme relied on range Fourier domain processing followed by azimuth time domain integration is proposed.In the simulation experiments,compared with the conventional time domain approach,the phase curves of the simulated raw data are shown in the case of ideal trajectory.In the case of actual trajectory,the error caused by the approximation of the distance model is analyzed,and the imaging results before and after motion compensation of the simulated raw data are obtained.Simulation results verify the accuracy and the effectiveness of two proposed simulation schemes.