One Dimensional Inverse Dielectric Profiling of Embedded Slabs by a Quadratic Approximation

In this paper the inverse problem of the determination of the dielectric profile of a slab embedded into a homogeneous half space starting from the knowledge of the scattered field for different illumination angles is considered. A comparison between the features of a linear and a quadratic distorted approximation of the scattering problem is carried out, in order to determine the kind of profiles that can be reconstructed. In particular, the investigation of the direct problem reveals that, under the linear approximation, only a limited number of Fourier harmonics of the profile give contribution to the scattered field. The use of the quadratic approximation allows to change the number and order of the harmonic that can be imaged. The dependence of the results on the dielectric permittivity of the host medium is also highlighted. Numerical examples support the theoretical considerations.     

Electromagnetic Prospection via Homogeneous and Inhomogeneous Plane Waves: The Case of an Embedded Slab

This paper deals with the linear approximation of the inverse scattering problem for a dielectric slab embedded into a homogeneous half-space. After a proper normalization of the scattered field, the problem at hand is recognized to be related to a Fourier transform inversion with limited data. This permits to resort to the well-known results available in signal processing in order to discuss about the class ofthe retrievable unknowns and the resolution limits achievable by inversion. In particular, the role of both homogeneous and inhomogeneous incident plane waves in carrying out information about the profile under test is investigated and the role played by the dielectric permittivity of the host medium in determining the information content of the scattered field is pointed out.     

非均匀介质中的场与波：理论及其在电测井中的应用

本文综述了非均匀介质中场与波理论近年来的研究进展及其应用成果，着重介绍了非均匀介质中的电磁场正演分析和反演计算中的各种高效数值方法，以及它们在电法测井数值模拟和成象研究中的成功应用。     

埋于偏心手征铁氧体介质圆柱中阻抗圆柱体的雷达截面积

本文利用分离变量法和圆柱函数的加法定理研究了平面波入射时埋于偏心手征铁氧体介质圆柱中阻抗圆柱体的电磁散射特性。文中给出了雷达截面积随各结构和电参数变化的关系曲线。     

FD－TD法计算色散媒质中埋入异常体的电磁散射

本文论述了ＦＤ－ＴＤ法用于计算地下浅层目标的电磁散射问题。推出了Ｄｅｂｙｅ型色散媒质中ＦＤ－ＴＤ法的迭代公式和吸收边界条件。通过将ＦＤ－ＴＤ法计算的结果与其它结果相比较，证实了该方法计算有耗媒质中电磁场问题的有效性。对瞬态脉冲在色散媒质中的传播特性进行了讨论。分别计算了典型地下目标的散射波形和波形堆积图。     

电磁格点理论在有耗介质涂层导体薄片上TE波散射中的应用

在ＴＥ波入射下，对于计算二维封闭导体柱散射问题所常用的磁场积分方程法，当用于导体薄片时将会失效．本文采用电磁格点理论和电场方法研究这个问题．结合二维介质柱的电磁格点方程，解决了有耗介质涂层导体薄片的ＴＥ波散射．文中给出计算实例．     

海上舰船在平面波照射下的半空间散射研究

本文研究了海面舰艇在平面波照射下的散射特性,为在该类问题中有效计入海面背景的影响,舍弃了以往文献中采用自由空间格林函数为内核求解的模型,而是利用介质半空间格林函数在海面建立电场积分方程,并采用GFB(广义前向后向法)算法结合MOM(矩量法)计算了海面以及海面舰船的感应电流分布以及双站雷达散射截面,对入射波角度、海面粗糙度、以及有船无船对海面电流分布及双站雷达散射截面的影响进行了讨论.