位场向上延拓是用来进行区域场局部场分离的，但是上延距离都是工作人员自己定，不稳定性大，最佳向上延拓高度法可以得到一个合理的上延高度-Upward continuation of potential field is used for local area farm field separation, but the extension distances are given their own staff, great instability, the best upward continuat