ABSTRACT The phase tensor of magnetotellurics is analysed in terms of its invariants with regard to axes rotation. These invariants are displayed as conic sections (ellipses), eigenvectors, and as Mohr diagrams. Attention is drawn to a supplementary ellipse which may be constructed to complement the usual phase tensor ellipse. The two ellipses together help convey the full information available from phase tensor analysis. For the cases of 1D and 2D regional structure, the ellipses, eigenvectors and Mohr diagrams show distinctive features, such as no preferred strike direction in the case of 1D, and a consistent strike (or across-strike) direction in the case of 2D. In the general case of 3D regional structure a “closest 2D strike” direction may be apparent, though there is a range of possibilities for this quantity. The range includes Bahr's regional strike estimates, which are shown to be given by the eigenvectors of the phase tensor. Generally in this paper, the phase tensor will be referred to as the CBB tensor, in recognition of its discoverers Caldwell, Bibby and Brown.

中文翻译：

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大地电磁学：CBB 或相位张量和 Bahr 1988 年的分析

摘要 大地电磁的相位张量是根据其关于轴旋转的不变量来分析的。这些不变量显示为圆锥截面（椭圆）、特征向量和莫尔图。注意一个补充椭圆，它可以被构造来补充通常的相位张量椭圆。这两个椭圆一起有助于传达相位张量分析中可用的完整信息。对于一维和二维区域结构的情况，椭圆、特征向量和莫尔图显示出鲜明的特征，例如一维情况下没有优选的走向，而二维情况下则是一致的走向（或交叉走向）。在 3D 区域结构的一般情况下，“最近的 2D 走向”方向可能是明显的，尽管这个数量有一系列的可能性。范围包括 Bahr' s 区域撞击估计，显示为由相位张量的特征向量给出。通常在本文中，相位张量将被称为 CBB 张量，以表彰其发现者 Caldwell、Bibby 和 Brown。