The geomagnetic field originates from interior dynamo currents and can be approximated well by a simple dipolar field in the vicinity of Earth's surface. Given that the dipolar field is induced by a current loop, it is possible to invert the loop parameters by tracing the sampled magnetic field geometry. Drawing on the analysis of field geometric structure with sampled field dataset, we develop, in this study, a new technique to invert the interior current source, which is based on a single circular current loop model. Unlike previous studies, this technique has the ability to separate and solve the optimal loop parameters successively, including the location of the loop center, the loop axis, the radius, and the carried electric current. Applications to the International Geomagnetic Reference Field and the sampled magnetic field dataset by the spacecraft of the Swarm mission demonstrate that our technique-derived loop center, loop axis, and magnetic moment are consistent with previous estimations by the eccentric dipole model, which shows the reasonability and effectiveness of this technique. Moreover, our technique can be reduced to fit an eccentric dipole model and is particularly useful for inversions of the geometry of interior current sources. Thus, it could be applied widely in the fields of planetary magnetism and palaeomagnetism. Further applications and constraints are discussed, with some cautions given.

中文翻译：

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基于单环电流回路模型的地磁场诊断新技术

地磁场源自内部发电机电流，可以用地球表面附近的简单偶极场很好地近似。鉴于偶极场由电流回路感应，可以通过跟踪采样的磁场几何形状来反转回路参数。在对采样场数据集进行场几何结构分析的基础上，我们在本研究中开发了一种新技术来反转内部电流源，该技术基于单个圆形电流回路模型。与以往的研究不同，该技术能够依次分离和求解最优回路参数，包括回路中心位置、回路轴、半径和载流电流。Swarm任务航天器在国际地磁参考场和采样磁场数据集的应用表明，我们的技术推导的环中心、环轴和磁矩与偏心偶极子模型的先前估计一致，显示了合理性和这项技术的有效性。此外，我们的技术可以简化为适合偏心偶极子模型，并且对于内部电流源的几何反演特别有用。因此，它可以广泛应用于行星磁学和古地磁学领域。讨论了进一步的应用和限制，并给出了一些注意事项。和磁矩与偏心偶极子模型的先前估计一致，这表明该技术的合理性和有效性。此外，我们的技术可以简化为适合偏心偶极子模型，并且对于内部电流源的几何反演特别有用。因此，它可以广泛应用于行星磁学和古地磁学领域。讨论了进一步的应用和限制，并给出了一些注意事项。和磁矩与偏心偶极子模型的先前估计一致，这表明该技术的合理性和有效性。此外，我们的技术可以简化为适合偏心偶极子模型，并且对于内部电流源的几何反演特别有用。因此，它可以广泛应用于行星磁学和古地磁学领域。讨论了进一步的应用和限制，并给出了一些注意事项。