Three-Dimensional Imaging Method for Pipeline Based on Magnetic Gradient Detection

Accurate detection of buried pipelines is vital for underground resource development and maintenance safety. This paper proposes a 3D imaging method based on magnetic gradient sensing to reduce operational risks and costs during pipeline maintenance. The method incorporates a region segmentation strategy and background field and magnetic moment estimation to provide prior information for inversion. An improved regularized inversion technique is developed, along with two novel error functions—Total Magnetic Anomaly (TMA) and angular deviation—supported by adaptive parameter optimization. A correlation-based metric is introduced to address the limitations of traditional evaluation methods. Simulations achieve a correlation coefficient of 0.94, and field tests validate the method’s effectiveness in imaging small ferromagnetic targets.