15
Interpreting The Forward
Horizontal Display
In the Horizontal display, the
SE-200 scans from left to
right across the boats bow. The forward scanning elements
in the transducer are positioned so that the plane of the
horizontal scan is angled downward approximately 10
degrees from the water’s surface (see sketch at left). This
downward angle is designed to help reduce the effects of
surface noise clutter when the water is choppy and to view
the bottom foward of the boat.
As the acoustic sound beam is projected away from the
boat, the cross-sectional diameter of the beam increases.
At a range of approximately 5 times the depth of the water
the sound beam will begin intersecting the bottom and
some of the sound energy that intersects the bottom will be
reflected back and will appear on the dislay as bottom
echos.
It is important to understand that when the
SE-200 is in the
Horizontal display mode, in shallow water - it will
typically show the bottom on the forward display. This
display information can be used to help understand the
structure of the bottom ahead of the boat, but the bottom
echos can also mask or be confused as fish targets.
The center picture and resulting screen display shows a
boat in 14.7 feet of water. The
SE-200’s forward range is
set to 100 Ft. Notice that the bottom is just starting to
show at about 75 forward.. A school of fish or bait is
shown about 50 feet to the right and forward of the ship’s
bow.
On the following page, two bottom situations are shown
along with the resulting
SE-200 Display.
Noise and Sensitivity Adjustments
The
SE-200 features an AUTO gain feature where it
continuously adjusts the gain to achieve the optimum
picture quality. The gain can also be adjusted manually to
allow for a reduction in gain to minimize the effect of
screen noise, or to increase the gain to show weaker
targets.
In the forward scanning modes, the gain setting is
especially important as too little gain will cause a loss of
target detection and too much gain will cause an increase
in screen noise. In the
AUTO mode, the SE-200 increases
the forward gain until there is a certain density of targets
Plane of Forward Scan is Angled 10 Degrees Downward From Surface.
Forward beam will reach bottom at approx. 5 times depth
Bait
100 ft Forward Range, Water Depth of 14.7 Ft
Bottom
Echos
Bait Ball
Summary of Contents for Sonar Engine SE-200
Page 1: ...1 SE 200 SONAR ENGINE...
Page 38: ...38 Notes...
