Triton Isis - Manual (Page 283)

June 2004 Isis® Sonar User's Manual, Volume 1
269
towfish altitude, is displayed in meters in the Parameter Display dialog box
and as a vertical white line in the Voltage window.
If you use (enable) slant range, make sure the seafloor bottom is
being tracked correctly. Otherwise, you might not get acceptable
results in your displayed imagery. See 10.7.2 (“Bottom Track and
TVG”).
The parameters for the Bottom Track dialog box are explained in
Table 10-5.
Table 10-5. Bottom Track parameters
Method
(drop-down
choices)
• choices are: Off, Amplitude, Gradient, or Manual.
• Off: All methods are suppressed.
• Amplitude: Channel, Level, and Holdoff are all
available (default).
• Gradient: When this is chosen, Level is dimmed and
unavailable.
• Manual : When this is chosen, Holdoff is dimmed
and unavailable.
Channel
(slider bar)
The bottom can be tracked on any available channel. Sliding
the bar to the right increases channel numbers (up to the
maximum number of channels that have been configured).
Level
(slider bar)
Setting a value for Level instructs Isis to use that value as a
minimum voltage threshold for applying TVG. Slide the bar
left for less Level, right for more. The default is to have no
amount of Level applied in TVG.
Holdoff
(slider bar)
Specify a minimum altitude from which Isis will begin to look
for the first return. Holdoff is inactive during Manual bottom
tracking.
Reset (button)
Resets the automatic bottom tracking algorithm if Isis loses
track of the bottom.
Chapter 10: Using the Window Menu