Inversion of airborne transient electromagnetic data based on reference point lateral constraint

• Published in: Journal of applied geophysics Vol. 202; p. 104675
• Main Authors: Zhang, Jifeng, Huang, Chaofeng, Feng, Bing, Shi, Yu
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.07.2022
• Subjects: Airborne transient electromagnetic method; Decay voltage; Lateral constrained inversion; Reference point; Decay voltage; Lateral constrained inversion; Reference point; Airborne transient electromagnetic method
• ISSN: 0926-9851
• DOI: 10.1016/j.jappgeo.2022.104675

The airborne transient electromagnetic method (ATEM) has become a popular tool in mineral and resource exploration due to its speed and high efficiency. The distance between two adjacent measured points is minuscule for a flight line because of the oversampling in the ATEM, which results in a sharp change in the horizontal direction. The conventional lateral constraint inversion method accumulates errors and has a significant calculation cost. Therefore, a laterally constrained, segmented inversion method based on a reference point is proposed to reduce errors and improve accuracy. Electrical information about the known logging data is employed as the lateral constraint of the reference point; alternatively, the inversion results of previous point can be used as lateral constraints, which guarantees a continuous inversion profile. The golden-section method is applied to solve the Lagrange multiplier to ensure a quick and effective convergence of inversions. Constraint inversions of a one-dimensional model show that the strategy converges quickly, and the inversion results are closer to the true resistivity of the model. Constraint inversion of a 2D model indicates that lateral constraints considerably reduce the discontinuity of a single-point inversion and smooths the inversion's resistivity pseudo-section. Finally, the effectiveness of the proposed algorithm is verified by the inversion of the airborne transient electromagnetic survey data in Xinjiang province. •The lateral constrained inversion based on reference point was applied to ATEM.•The golden section method is used to determine the Lagrange multiplier.•Segmented inversion strategy was used improve the inversion speed and accuracy.