基于曲波变换的航空电磁数据调平方法研究

航空电磁法由于高效和高精度的特点广泛应用于地质填图、矿产资源、地下水、及环境与工程等勘查.然而,航空电磁系统处于动态环境,噪声影响严重,航空电磁数据处理至关重要.航空电磁数据噪声除随机成分外,还包括有各种效应引起的畸变,数据去噪需要依据噪声特征进行处理.航空电磁数据调平是航空电磁数据处理中至关重要的步骤,它能有效去除数...

Leveling of airborne electromagnetic data based on curvelet transform

Airborne Electromagnetism(AEM)iswidely used in geological mapping,mineral exploration,groundwater,environmental and engineering investigations for its high efficiency and effectiveness.However,an effective data processing is important for a successful EM survey due to dynamic and noisy environments.Except for random part,the AEM noise encompasses yet those from different effects,so that they must be removed separately based on their characteristics.Leveling is a critical procedure in AEM data processing that reduces errors arising from acquisition circumstances of the aircraft.The traditional leveling methods have the limitations of low efficiency and data distortion.To overcome these disadvantages,we propose a new leveling method based on the curvelet transform.Due to its multiscale and multi-directional characteristics,the leveling errors of this method can be extracted and removed without much damage to the data.Meanwhile,this method allows us to do the leveling in irregular survey areas,without needing to divide the survey area.This makes the leveling procedure more efficient and applicable.To test the feasibility of this curvelet-based leveling,we apply it to both synthetic and survey data acquired by a frequency-domain EM system from Waterford,Ireland.The experiments show that this leveling method can not only remove the leveling errors but also well retain the signal.