Abstract: The drone-based TEM ( Transient Electromagnetic) system combines the advantages of being lightweight, flexible, efficient and safe, with broad application prospects. However, it also produces various noises that affect the detection performance in practical applications. Based on the dipole model and DE (Differential Evolution) algorithm, targets are located, noise sources and types are analyzed through field tests, and the influence of noise on system positioning performance is studied. The results show that the system is affected by static noise, low-frequency noise caused by coil rotation/ swing, and drone noise. When only affected by static noise with target depth of 80 ~100 cm, the positioning error does not exceed 9 cm, and the inversion depth is shallower than the actual depth. When coil rotation/ swing amplitude is small, low-frequency noise has minor influence. As amplitude increases, the influence grows significantly, with positioning error increasing to 29 cm and inversion depth becoming deeper than actual depth. Drone noise also increases positioning error to 12 cm, with inversion depth deeper than actual depth. The research determines the types, sources and effects of noise, and guides the subsequent system optimization. 

Key words: unexploded ordnance, drone-based transient electromagnetic system, differential evolution algorithm, noise influence