航磁梯度数据曲化平分析

• 作 者: 谢汝宽 王平 段树岭 王金龙 安战锋 刘浩军
• 机 构: 中国国土资源航空物探遥感中心,国土资源部航空地球物理与遥感地质重点实验室,
• 出 处: 地球物理学进展
• 发表日期: 2015年06期
• 关键词: 航磁 梯度 航磁梯度 延伸长度 实际资料处理 曲化平 物性 理论模型计算 反演方法 等效源

航磁梯度表征空间磁场的变化率,主要反映磁场的高频信息,较航磁总场随高度增加而衰减更快,其受地形起伏或飞行高度变化的影响更为严重,曲化平研究对航磁梯度数据的应用具有重要意义.本文在分析航磁梯度特点的基础上,针对航磁梯度数据的曲化平问题,采用等效源技术及位场物性反演方法实现了航磁梯度曲化平.讨论了等效源的设置问题,等效源采用单层向下延伸的长方体,延伸长度通常为其宽度的5~20倍,避免了多层等效源反演结果中物性分布趋近于地表,从而导致曲化平误差较大的问题,并节省了计算时间.理论模型计算与实际资料处理表明该曲化平方法可靠,具有实用性.

Aero-magnetic gradient characterizes the rate of change of the spatial magnetic field, which mainly reflects the high-frequency information of the magnetic field. It decays more rapidly than the altitude of the aeronautic magnetic field, which is more seriously affected by the fluctuation of the terrain or the flight altitude. The application of aero-magnetic gradient data is of great significance.In this paper, based on the analysis of the characteristics of aero-magnetic gradient, aiming at the curve-leveling problem of aeromagnetic gradient data, the equivalent magnetic field gradient This paper discusses the problem of setting the equivalent source. The equivalent source uses a rectangular parallelepiped extending downwards from one layer. The extension length is usually 5 ~ 20 times of its width, which avoids the distribution of physical properties in the multi-layer equivalent source inversion Close to the surface, resulting in the problem of large leveling error and saving the calculation time.The theoretical model calculation and the actual data processing show that the method is reliable and practical.