Humminbird 1197C SI - Manual (Page 59)

Understanding Side Imaging
(1197c SI Combo models only)
It is important to understand how Side Imaging technology produces the display available on the 1100
Series™. The images you see on the display are produced using sonar technology. The special transducer
produces three distinct beams – one beam facing down and two beams pointing out to the side. These “side
beams” are aimed at right angles to the path of the boat and, unlike the “down beam” which provide conical
coverage, the side beams provide coverage which is very thin front to back, yet very wide top to bottom.
The narrow aspect (front to back) of the beam illuminates a small strip of the bottom perpendicular to the
direction of the boat. Each time the unit “pings”, a strip of data representing all the echoes received by the
transducer, are put together on the display to form the image that you see. The rows closest to the boat
icon at the top of the display are the most recent sonar data. The information is scrolled down the screen
as new data, drawn at the top of the screen, becomes available.
The side beams can be operated at one of two frequencies: 455 kHz or 800 kHz. Selecting 800 kHz
produces the sharpest image while selecting 455 kHz provides greater bottom coverage area. It is
important to understand that when the boat turns, the strips to one side will begin to overlap and the
strips on the other side will fan out, providing some distortion to the image. Side beams look out
360 feet, with a depth limitation of 100 to 150 feet, depending on the contour of the bottom and when
the side beam frequency selection is set for 455 kHz. Please see the Side Imaging Sonar Tutorial at
www.humminbird.com for a more detailed explanation.
Your Side Imaging transducer also provides traditional sonar imaging at 200/83 kHz.
130° Total Coverage
60°
83kHz
20°
200kHz
55°
800kHz
55°
800kHz
Side Imaging
800 kHz provides highest resolution with 130° total beam width
180° Total Coverage
60°
50kHz
86°
455kHz
86°
455kHz 20°
200kHz
Side Imaging
455kHz-Maximum Coverage
455 kHz provides maximum coverage with 180° total beam width
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