基于时间域电磁系统的近地表小目标识别

时间域电磁系统被广泛地用于管线探测、考古和未爆物排查等近地表小目标探测领域,但异常目标的特性反演是一个难点,造成探测的虚警率和排查成本大大提升。提出一种三维正交磁偶极子等效模型和一种目标参数综合方法,通过反演等效磁偶极子的时间衰减特性并由此综合出目标的大小、材料和形状等参数。基于所研制出的便携式时间域电磁系统来验证方法的有效性,实验表明,基于磁偶极子时间衰减特性综合出的目标特征均可以有效地对目标进行识别,为近地表小目标特性识别的应用奠定了基础。

Discriminating subsurface anomaly with time domain electromagnetic induction

Time domain electromagnetic (TDEM) method is widely used in detecting subsurface objects such as pipelines, unexploded ordnance (UXO) and archaeological studies. But the characteristics inversion of anomaly is still a challenging problem which causes the increase of false alarm rate and cost of labor. This paper proposes a three dimensional orthogonal equivalent magnetic dipole model and a target parameter synthesis method. With the proposed model and method, the target size, material and shape parameters can be synthesized by the time attenuation characteristics of the equivalent magnetic dipole. The proposed model and method is tested by the developed TDEM system. Experimental results indicate that the model can reproduce the response of subsurface objects, and the parameters of the dipoles can be used to estimate the characteristic of the object. These features can lay solid foundation for identifying subsurface objects.