论文部分内容阅读
利用垂直天线阵观测得到的电磁场信息建立目标泛函,从电磁波抛物方程传播模式出发,利用偏微分方程最优控制中的伴随方法研究大气折射率廓线反演问题.针对反演的不适定性,采用正则化思想对目标泛函进行改造,并根据变分同化思想构建反演迭代格式.数值模拟试验验证了理论算法的可行性.由于采用分步Fourier算法求解电磁波抛物方程传播模式和伴随模式过程中产生的固有误差随着传播距离的增加累积增大,反演廓线在传播距离较远时不能收敛于观测廓线.在这种情况下,引入较好的初猜廓线和背景场可以有效地改进反演结果.
The objective function is established based on the electromagnetic field information of the vertical antenna array. Based on the propagation model of the electromagnetic wave parabolic equation, the inversion of atmospheric refractive index profile is studied by using the adjoint method in the optimal control of partial differential equations. In allusion to the ill-posedness of inversion, The objective function is transformed by using regularization theory, and the iterative iterative format is constructed according to the idea of variational assimilation.Numerical simulations verify the feasibility of the theoretical algorithm.Because the fractional Fourier algorithm is used to solve the electromagnetic wave parabolic equation propagation mode and accompanying mode process The inherent error increases cumulatively as the propagation distance increases, and the inversion profile can not converge to the observation profile when the propagation distance is far .In this case, the introduction of a better initial guess profile and background field can Effectively improve the inversion results.