Bi-cubic spline interpolation

This interpolation method is an extension of the bilinear interpolation method. It requires as well a grid-like arrangement of the stations to be interpolated. Based on this grid, it performs a spline interpolation for the north-south meridians, followed by an east-west meridian interpolation of the interpolated data of the north-south spline.

Results of bi-cubic spline interpolation are usually smoother than that from other interpolation methods.

More details about this method can be found in the manual, chapter on Interpolation of meteorologic input data