Convolution Filter Along Array

Use the Convolution Filter > Along Array menu option from Database Tools > Array Channels, (VACVFILT GX), to apply a convolution filter to an array channel along the array (row). The filter can be defined in a filter file or in a comma delimited string.

Convolution Filter Along Array dialog options

Input channel	Name of the Input Channel. It must be an array channel. Script Parameter: VACVFILT.INCH
Output channel	Name of the output channel (created if does not exist). If the 'Output channel' entry is empty, filter results will be saved in the same input channel and the original data in the input channel will be overwritten. When an output channel name is given, the channel will be created if it does not exist in the database. However, if the output channel already exists in the database, it must have the same array size as the input channel. Script Parameter: VACVFILT.OUTCH
Filter file	Filter file name Script Parameter: VACVFILT.FILE
Or filter (c1, c2, ...)	A filter string, comma delimited Script Parameter: VACVFILT.FILTER

Application Notes

The VACVFILT GX can be used to apply any even or odd-length convolution filter to an array channel along the array (row). If the filter has an even length, the resulting filtered array will start one-half element past the start of the original data.

Maximum entropy prediction is used to pad data to the ends of the array data, and to fill holes in the data. The ends of the data and holes are removed after applying the filter.

A filter file must contain one filter coefficient on each line. Comment lines (those beginning with a '/' character) and blank lines are skipped.

Coefficients in a filter string must be comma delimited. If a filter string is defined, the filter file is ignored, even if one is specified.

Standard filters located in GEOSOFT:

FRASERP4.FLT	Positive even fraser filer (-1, -1, 1, 1)
FRASERM4.FLT	Negative even fraser filer (1, 1, -1, -1)
FRASERP5.FLT	Positive odd fraser filer (-.5, -1, 0, 1, .5)
FRASERM5.FLT	Negative odd fraser filer (.5, 1, 0, -1, -.5)
LAPLACE.FLT	Laplace filter (-0.5, 1, -0.5)