多频电磁波测井的时域差分法正演模拟

A FINITE-DIFFERENCE TIME-DOMAIN METHOD APPLYING IN NUMERICAL FREQUENCY ELECTROMAGNETIC-FIELD CALCULATING

时域差分法作为 Ｍａｘｗ ｅｌｌ方程的直接解法，是由叶（ Ｙｅｅ）氏首先提出的，近些年受到国内外研究人员的广泛重视。它在波场计算中的普遍应用源于它自身的一些优点：①不受物理模型几何形状的限制；②不受制于散射因素；③是一种对瞬变问题的直接解法。给出了柱坐标系下 Ｍａｘｗ ｅｌｌ方程的时域差分公式，验证了方法软件的稳定性和计算的精度，对几种地层模型进行了模拟计算，取得良好效果。

As a directively method of Maxwell equations, which was first put forward by Yee, FKTD Method has received of the internal and external research workers considerable attention. Recently, the popularity in wave-field calculating of this methok seems from its own advantages. 1.It is not limited to a specific geometry, 2.It don not restrict the constitutive parameters of a scatter. 3.It provides a direct solution to problems with transient illumination. In this paper. We tried to give the FDTD formulation of Maxwell equations in circular cylindrical coordinates. Through the calculating experiment, verified the steady and pricision of this method.