频率域航空电磁法地形影响和校正方法

Topographic Effects and Correction for Frequency Airborne Electromagnetic Method

为了研究地形对频率域航空电磁法的影响程度,以及如何有效提取由于地形产生的航空电磁场,笔者利用频率域有限差分法开展了复杂地形条件下的频率域航空电磁响应计算和分析研究。计算结果表明,坡度较陡的地形对频率域航空电磁响应影响较大(尤其在沟谷位置地形影响最大),以至于增加了电磁异常的复杂程度,影响了电磁异常的解释结果。在综合研究的基础上,采用二维和三维的地形校正方法对典型地形地电模型进行校正,有效去除和压制了地形引起的电磁干扰异常,突出了异常体引起的电磁异常,提高了频率域航空电磁的解释效果。

In order to study the topographic effects of AEM and effectively extract the electromagnetic field from topographic effects,the authors research the response of the frequency airborne electromagnetic method in complex terrain.The result indicates that a steep slope has a significant influence to the response of the frequency airborne electromagnetic method,especially,terrain influence will be the greatest at the place of gully.It complicates the electromagnetic anomaly,and affects the interpretation of the electromagnetic anomaly.Based on the comprehensive research,the authors correct the typical earth electrical model using 2Dand 3Dtopographical correction method,remove and suppress the electromagnetic anomaly caused by the topographic interference,highlight the anomaly of anomalous body,improve the effectiveness of the interpretation of the frequency airborne electromagnetic method.