Downward continuation of airborne geomagnetic data based on two iterative regularization methods in the frequency domain

• Main Authors: Xiaogang Liu, Yingchun Li, Yun Xiao, Bin Guan
• Format: Article
• Language: English
• Published: KeAi Communications Co., Ltd. 2015-01-01
• Series: Geodesy and Geodynamics
• Subjects: Downward continuation; Regularization parameter; Iterative Tikhonov regularization method; Iterative Landweber regularization method; Fast Fourier transform (FFT); High-frequency noise; Frequency domain; Airborne geomagnetic surveying
• Online Access: http://www.sciencedirect.com/science/article/pii/S1674984715000063

Downward continuation is a key step in processing airborne geomagnetic data. However, downward continuation is a typically ill-posed problem because its computation is unstable; thus, regularization methods are needed to realize effective continuation. According to the Poisson integral plane approximate relationship between observation and continuation data, the computation formulae combined with the fast Fourier transform (FFT) algorithm are transformed to a frequency domain for accelerating the computational speed. The iterative Tikhonov regularization method and the iterative Landweber regularization method are used in this paper to overcome instability and improve the precision of the results. The availability of these two iterative regularization methods in the frequency domain is validated by simulated geomagnetic data, and the continuation results show good precision.