基于零边界值Kriging插值的地磁异常场稳定向上延拓法

Stable upward continuation method of geomagnetic anomaly field based on zero-boundary Kriging interpolation

针对位场向上延拓存在边界误差的问题,根据向上延拓的原理对边界误差产生的原因进行了分析,提出了补充零边界值并用普通Kriging法对数据进行插值的方法,对插值后的区域在频域进行向上延拓,并采用绝对误差最大值占平面磁异常最大值的比例作为误差评价标准。仿真结果表明:所提的方法优于不扩边和最小曲率法扩边的向上延拓方法;向上延拓200倍点距时,误差可以比未扩边时的误差减小89.91%。实测数据延拓结果表明该方法是有效的。

Aiming at the problem of boundary error in the upward continuation of the potential field,the reasons for the boundary error were analyzed based on the principle of upward continuation.A method of supplementing the zero boundary value and using the ordinary Kriging method to interpolate the data was proposed.The area after interpolation was continued by the frequency domain me-thod.The ratio of the maximum absolute error to the maximum magnetic anomaly in the plane was used as the error evaluation standard.The simulation results show that this method is better than the upward continuation method of non-extended edge and minimum curvature method.When the upward continuation distance is 200 times the dot pitch,the proposed method can reduce the error by 89.91%compared with the unextended edge.The continuation result of the measured data shows that the method is effective.