最小二乘法在计算矿井瞬变电磁超前探测盲区中的应用

THE APPLICATION OF LEAST SQUARE ALGORITHM TO THE ADVANCED DETECTIONOF THE BLIND AREA USING MINE TRANSIENT ELECTROMAGNETIC METHOD

为解决矿井瞬变电磁超前探测的盲区问题,通过最小二乘法对仅由地质异常体产生的电磁场数据进行处理,得到一个测点的回归方程。利用该方程对盲区内的视电阻率值进行适当预测,得到的视电阻率值接近于煤层真实电阻率值,且曲线变化平稳。利用得到的新视电阻率曲线接反推盲区内的观测信号曲线,该曲线可以看作从盲区内混杂信号中分离出的纯二次场响应,从而提高矿井瞬变电磁超前探测在早期的效果。

The authors have obtained a regression equation about one measuring point using the least square algorithm which acts on the electromagnetic field created only by geological anomaly body instead of by mixed signal. The apparent resistivity which is just on the verge of the real electrical resistivity of the coal seam can be predicted appropriately by using this equation. At the same time, the change of the apparent resistivity curve after using least square algorithm is very stable. The value of this new apparent resistivity in the blind area can be used to figure out the value of the observed signal inside the blind zone. Then the response message of unmixed sec- ondary field which is caused only by the geological anomaly body comes out, and this unmixed secondary field can be regarded as the filed separated from the mixed filed, and it brings a much better result at the early stage of advanced detection.