Journal of Engineering Science and Technology Review (Jul 2013)
Application on Polynomial Approximation Method in Airborne Geological Exploration
Abstract
Coil motion noise is the main noise source in AEM data caused by the movement of the receiver coil in the Earth’s magnetic field. The characteristics of both time domain and frequency domain of motion noise are analyzed. In this paper we present a scheme of removing motion noise which employs polynomial to represent motion noise for each half cycle. A set of equations are set up according to the characteristics of AEM data, and Lagrange method is employed to solve minimum problem with two constraint conditions together. The polynomial coefficients are calculated by matrix inverse and finally motion noise is subtracted from the AEM data half cycle by half cycle. Polynomial approximation method is applied to the synthetic data contaminated by low frequency motion noise comparing with traditional high pass filter method. The corrected AEM data shows polynomial approximation method is more effective in dealing with motion noise.