分布式星载干涉SAR基线设计与性能分析

基于线性化开普勒方程给出了分布式SAR卫星的轨道要素计算公式,分析了分布式星载干涉SAR的高程测量精度、速度测量精度以及改善空间分辨率的性能指标,建立了分布式SAR卫星的空间几何模型,结合编队构形设计进行了极限基线分析;在此基础上提出了一种通用的三维编队飞行分布式星载干涉SAR基线设计方法.基于L波段分布式SAR卫星进行了编队轨道参数设计,给出了干涉基线的仿真结果,并通过系统性能分析验证了基线设计方法的有效性.

Study on the Scattering of Two-Dimensional Electromagnetic Field Based on Symplectic Integrator Method

The symplectic integrator method is a new time-domain method which can preserve the symplectic structure of the Hamiltonian system.Maxwell Equations is in fact an infinite-dimensional Hamiltonian system,so this method can be used for electromagnetic field simulation.In this paper,A class of symplectic difference scheme which is based on an explicit symplectic partitioned Runge-Kutta(PRK) method is proposed,and it is demonstrated that the proposed method is applicable to the area of numerical computations for the scattering of electromagnetic waves by successful numerical simulation of the total field of a two-dimensional square metal conducting target.The results show that under the same mesh-point density,time steps and spatial discretization conditions,the accuracy of the low-order symplectic methods is equivalent to the standard FDTD method,butthe symplectic methods can reduce the required memory and computational time,for it can describe the whole electromagnetic field with fewer functions compared with the standard FDTD method,especially the 1st-order symplectic method takesonly 60% of the computational time of the FDTD method,thus shows the symplectic PRK method is promising.