Automatic FFT Preparation

Use the Automatic FFT Preparation dialog to set the parameters for the GM-SYS 3D model’s internal FFT grid preparation.

Initial Dialog Options

Minimum % to Expand grids	Grids will be expanded by at least this percentage of their original size in preparation for FFT. Default is 50%
Shape of output grids	Default is rectangular. Use this choice box to force grid dimensions to be equal.

Application Notes

Internal expansion/filling works reasonably well for grids that have zero trend, using the default values. This GX calls "GRIDFILL.GX" using the following parameters rather than the standard Oasis montaj defaults. If you want to see exactly what the automatic preparation produces, use these settings:

Roll off method	SQUARE
Distance at which to roll to 0	0
Maximum prediction filter length	-1
Maximum area to define filter	0
Roll off base	blank
Maximum grid amplitude allowed	-1.0
Maximum edge amplitude allowed	-1.0
Width from edge to start limiting	0
Number of convolution passes	1