Humminbird 997c Combo, 900 Series manual Understanding Side Imaging

Understanding Side Imaging

It is important to understand how Side Imaging technology produces the display available on the 900 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.

455 kHz provides maximum coverage with 180° total beam width

Side Imaging

455 kHz-Maximum Coverage

84°	20°	84°
455 kHz		455 kHz

200 kHz

60°

83 kHz

180° Total Coverage

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.

800 kHz provides highest resolution with 130° total beam width

Side Imaging

55°	20°	55°
800 kHz	200 kHz	800 kHz

60°

83 kHz

130° Total Coverage

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