Calculate Derivatives from Total Field Grid

Use the Calculate Derivative Grids option (UXDXDYDZ GX) to compute the vertical and horizontal derivative grids from an existing total field magnetic grid.

Calculate Derivatives from Total Field Grid dialog options

Input total field grid	Input total field grid Script Parameter: UXDXDY.DZTF
X-derivative output grid	Output X-derivative grid Script Parameter: UXDXDYDZ.DX
Y-derivative output grid	Output Y-derivative grid Script Parameter: UXDXDYDZ.DY
Z-derivative output grid	Output Z-derivative grid (1VD) Script Parameter: UXDXDYDZ.DZ
Z-derivative Method	Select FFT method (0) or Convolution method (1) (Default is FFT method). Script Parameter: UXDXDYDZ.METHOD

Application Notes

The name of the existing total magnetic field grid is required. This may be selected from the drop down list. The names of the first vertical derivative grid and the two horizontal derivative grids are also required. If the derivative grid names chosen already exist, a dialog box will appear asking if you want to overwrite them.

The default Z-derivative method is "FFT method". However, in the case of a very large grid (over 4000x4000) using the "Convolution method" will save a large amount of processing memory and time.