日本遗弃化学弹问题，被称为中日两国之间的重大历史遗留问题。日本遗弃化学弹的探测技术，是多年来解决该问题的重大技术挑战。本文基于自研的磁梯度探测仪，主要研究适用于日本遗弃化学弹的目标定位方法与三维成像方法。 本文基于自研仪器采集的数据，首先建立遗弃化学弹的磁偶极子模型和均匀磁化长方体网格模型，分别为定位方法和成像方法提供正演的模型基础；然后基于磁偶极子模型，通过改进的欧拉方法对模型参数进行反演，建立遗弃化学弹定位方法；最后基于均匀磁化长方体网格模型和定位方法，在正则化反演的框架下对目标函数进行优化求解，建立遗弃化学弹三维成像方法。论文的主要创新点如下： （1）建立了日本遗弃化学弹的定位方法。该定位方法由三个步骤实现，主要包括：首先建立了基于多分辨率线性回归的数据预处理方法，用于从原始数据中提取出仪器姿态较为稳定的测点组；随后改进了欧拉反褶积法，将卷积操作从正方形滑动窗口内的数据置换为时间上连续的数据，并提出了将背景场作为未知量进行反演，获得了目标位置的多个解；最后基于归一化磁源强度去除明显错误的解，并利用DBSCAN方法对解进行聚类，获得遗弃化学弹的定位结果。此方法在仿真实验中的定位误差均低于\SI{0.1}{m}，在实测实验中的定位误差均低于\SI{0.15}{m}。 （2）建立了日本遗弃化学弹的三维成像方法。首先建立了重点探测区域分割方法，用于减少后续步骤的计算量；同时建立了目标背景场与磁矩估计方法，用于为后续步骤提供先验信息。在此基础上，改进了正则化反演方法，设计了TMA误差函数与角度误差函数，实现了标量信息与矢量信息的解耦，在保证反演可靠性的前提下提高了成像精度；进而提出了目标函数参数的自适应调整方法，在数据误差估计不准的情况下也可以取得较高的成像精度，从而建立了遗弃化学弹三维成像方法。仿真实验表明，此方法成像结果的相关性指标为0.94；实测实验表明，此方法实现了较为准确的遗弃化学弹三维成像。 论文建立了日本遗弃化学弹的定位方法与三维成像方法，在未爆弹探测的定位和成像方法方面具有理论创新性，指导了探测作业，降低了探测成本。

The issue of Japanese abandoned chemical bombs is a significant historical legacy issue between China and Japan. The detection technology of Japanese abandoned chemical bombs has been a major technical challenge for many years. This thesis is based on a self-developed magnetic gradient detector and mainly studies target localization and three-dimensional imaging methods applicable to Japanese abandoned chemical bombs.Based on the data collected by the self-developed detector, this thesis first designs a magnetic dipole model and a uniform magnetized rectangular grid model for abandoned chemical bombs, respectively providing forward modeling for localization and imaging methods. Then, based on the magnetic dipole model, the model parameters are inverted using the improved Euler method to establish the localization method for abandoned chemical bombs. Finally, based on the uniform magnetized rectangular grid model and localization method, the objective function is optimized and solved in the framework of regularized inversion to develop the three-dimensional imaging method for abandoned chemical bombs. The main innovations of this thesis are as follows:(1) A localization method for Japanese abandoned chemical bombs is proposed. The method is realized in three steps, mainly including: firstly, a data preprocessing method based on multi-resolution linear regression is designed to extract stable measuring point groups from raw data; then, the Euler deconvolution method is improved to replace the convolution operation of data in square sliding window with time-continuous data, and the background field is proposed as an unknown variable for inversion to obtain multiple solutions for the target position; finally, the obvious wrong solutions are removed based on the normalized magnetic source strength, and the DBSCAN method is used to cluster the solutions to obtain the localization result of the abandoned chemical bomb. The positioning error of this method in the simulation experiment is below \SI{0.1}{m}, and in the field experiment, it is below \SI{0.15}{m}.(2) A three-dimensional imaging method for Japanese abandoned chemical bombs is proposed. Firstly, a key detection area segmentation method is developed to reduce the computational burden of subsequent steps; at the same time, a target background field and magnetic moment estimation method is developed to provide prior information for subsequent steps. On this basis, the regularized inversion method is improved, the TMA error function and the angle error function are designed, scalar information and vector information are decoupled, and the imaging accuracy is improved while ensuring the reliability of inversion. Then, an adaptive adjustment method for objective function parameters is proposed, which can achieve high imaging accuracy even in the case of inaccurate data error estimation, thereby developing a three-dimensional imaging method for abandoned chemical bombs. The simulation experiment shows that the correlation metric of the imaging results of this method is 0.94, and the field experiment shows that this method achieves accurate three-dimensional imaging of abandoned chemical bombs.This thesis proposes the localization and three-dimensional imaging methods for Japanese abandoned chemical bombs, which have theoretical innovation in the localization and imaging methods of unexploded ordnances, and benefit detection operations and reduce detection costs.