Triton Isis - Manual (Page 147)

June 2004 Isis® Sonar User's Manual, Volume1 133
Definitions of terms used to describe the relationships of various distances
depicted in Figure 8-8 are:
Offset:
a fixed value equal to the distance between the towpoint
and the navigation antenna or ship’s reference point,
entered manually.
Height of Towpoint: a fixed value equal to the height of the towpoint above
water level, entered manually.
Cable Out: a variable value equal to the amount of cable from the
towpoint to the towfish. The value can be acquired
automatically from a cable-counter device via a serial
port, or it can be entered manually by the operator.
Fish Depth: a variable value equal to the depth of the towfish. The
value can be acquired automatically from a fish-mounted
depth sensor via a serial port, or it can be entered
manually by the operator.
Layback: the total horizontal distance from the towfish to the
navigation antenna or vessel’s reference point. The
value can be acquired automatically from an external
navigation computer via a serial port; or it can be
calculated by Isis from Offset, Height of towpoint,
Cable out and Fish Depth; or it can be manually input
by the operator.
8.7.1 Using the Layback Correction Dialog Box
Clicking View→Layback opens the Layback Correction dialog box
(Figure 8-9).
Chapter 8: Using the View Menu