Abstract:We put forward local-coordinate spline function method:a new method for computing the derivative of geophysical anomaly. This local-coordinate spline function method can be described by the following essential points: ·There is an ordered point sequence in a plane. ·Adjacent points are connected by line segments. ·A chord between two adjacent points is taken as x axis,and its normal line as y axis. ·Establish a curve equation of certain continuity at the inside points,which is then called spline function in Local coordinate system. ·For the practical application,the derivatives obtained from local spline function must be converted into the derivatives in observation plane coordinate system.
This method is very applicable to the case of steep anomaly,and its accuracy is one grade higher than that of B spline function method.