Intermec TRACKER PRO 128 - Manual (Page 7)

5
depth of the water changes, the range
changes as necessary in order to retain a
bottom representation on-screen.
When in Auto mode, the horizontal line
at the top of the screen is the “zero
line,” representing the surface of the
water. Occasionally there is a gap in this
line. This gap indicates the unit is up-
dating the display even if the bottom is
not visible on-screen, or if the bottom
information is not changing.
New sonar information appears on the
right side of the graphic area of the dis-
play and moves to the left as new infor-
mation is displayed. The Tracker unit
automatically selects the appropriate
depth range to show the depth of water beneath the transducer. This
range is selected so the bottom representation is typically shown about 2/3
down the display.
Bottom. The graphic depiction of the
bottom provides an effective tool for
understanding the composition of the
bottom. If the bottom is hard and
smooth, the bottom depiction is narrow
and dense. If the bottom is soft mud or
sand, the depiction will be thick and less
dense. This indicates much of the signal
is absorbed by the soft bottom. If the
bottom is rocky or rugged in composi-
tion, the depiction is of varying density
and textured in appearance.
Wave action also affects the bottom
depiction. The information drawn is a
distance measurement, so if the boat is
USING THE TRACKER UNIT
WHAT YOU SEE ON-SCREEN
Water Depth
Bottom Depiction
Depth Range
Figure B
Zero Line
Surface Clutter Rocky Bottom
Soft Bottom Hard Bottom