Triton Isis - Manual (Page 200)

June 2004 Isis® Sonar User's Manual, Volume1 186
In the work area window you can do any of the following:
• Specify a kernel size by using the up and down arrows on the matrix
indicator.
• Type one or more values for any of the positions in the kernel. If
fewer elements are specified than are indicated by the kernel
dimensions, the omitted elements will be set to zero. If more elements
are specified than indicated, they will be ignored. If you do edit or add a
value, the Sum of kernel adjusts to accommodate your changes.
• Specify a divisor to be some number other than the sum of the kernel
elements. A displayed choice of 0 means “no divisor” (not “divide by 0”).
Divisors specified in the Other box can be in the range -32768 to
+32767.
• Apply the displayed custom filter to the Isis configuration. You also
have to click the Custom button in the Sweep Spatial Filter dialog box or
Continuous Spatial Filter dialog box before the filter will sweep over the
image.
• Import (Load, equivalent to open) a previously saved set of kernel
values. The default file extension for custom spatial filter files is CSF, but
you can use another file extension. If you want to prevent the file from
being overwritten accidentally, check the Open as read-only check box
in the Open dialog box.
• Save the currently displayed custom filter by overwriting the values
of a previously saved file of the same name displayed in the File area of
the work window.
• Save the currently displayed kernel values to a new file using Save
As.... Uncheck the Open as read-only check box to overwrite a file that
had been loaded as read only.
6. Choose Apply or OK to update the current custom filter.
OK updates the current custom filter and closes the work area window.
Apply also updates the current custom filter but does not close the work
area window.
7. Choose Custom filter type from either the Sweep or Continuous Spatial
filter dialog box to see the effect of your custom filter.
9.8 Beam Angle, Grazing Angle
You can clean up certain aspects of your data imagery by applying beam angle
compensation and grazing angle compensation.
Chapter 9: Using the Tools Menu