综合孔径干涉辐射计系统仿真

为预测实际综合孔径干涉辐射计(synthetic aperture interferometric radiometer,SAIR)的系统性能,提出了一种基于系统信号流图的SAIR系统仿真技术,通过计算信号路径上各节点信号的均值和方差,生成高斯分布随机视函数集,采用离散傅里叶变换(discrete fourier transform,DFT)算法重构视场内的亮温分布,经过两点法校准得到最终的SAIR图像。利用该技术仿真了T型天线配置、每臂30元的SAIR系统在不同积分时间下对均匀背景上热点源的成像,仿真图像的信噪比与理论值吻合良好。仿真了同样天线阵配置,不同基线误差、通道幅相误差和不可分幅相误差水平下非理想SAIR系统的成像效果和亮温误差。仿真结果证明了该仿真技术的有效性。

Synthetic aerture interferometric radiometer system simulation

To evaluate the performances of an actual synthetic aperture interferometric radiometer(SAIR) system,a technology of system simulation of SAIR based on the signal routing chart is introduced.The formulas of the mean values and variances of the signals at each node of signal routing paths are derived out.Then a set of Gaussian-distributed random "visibility functions" is generated.A DFT algorithm is applied to reconstruct the bright temperature distribution in the filed of view.The final image of BT is achieved after two-point-method calibration and scaling.SAIR sysetm with "T"-type antenna comfiguration of 30 elements per-arm is simulated.The simulated image Signal-Noise-Ratio conformed the theoretical value perfectly.System with the same configuration and variety levels of baseline error,amplitude-phase unbalance of receiver channels and nonseparable amplitude-phase error are simulated.Typical imaging results as well as bright temperature errors are presented and validity of this technology is verified.