Humminbird 767 manual Understanding Sonar History, Real Time Sonar RTS Window, Freeze Frame

531427-1_C - 767_Man_Eng.qxd 10/25/2005 10:29 AM Page 20

Understanding Sonar History

It is important to understand the significance of the 700 Series™ Fishing System display. The display does NOT show a literal 3-dimensional representation of what is under the water. Each vertical band of data received by the control head and plotted on the display represents something that was detected by a sonar return at a particular time. As both the boat and the targets (fish) may be moving, the returns are only showing a particular segment of time when objects were detected, not exactly where those objects are in relation to other objects shown on the display.

Real Time Sonar (RTS®) Window

A Real Time Sonar (RTS®) Window appears on the right side of the display in the Sonar View only. The RTS® Window always updates at the fastest rate possible for depth conditions and shows only the returns from the bottom, structure and fish that are within the transducer beam. The RTS® Window plots the depth and intensity of a sonar return. (See Sonar Menu: RTS® Window) .

Freeze Frame

Freeze Frame - Pressing any arrow on the 4-WAY Cursor Control key will freeze the screen and a cursor will be displayed on the screen. The cursor can be positioned on the display using the 4-WAY Cursor Control key to determine the depth of any sonar return. The RTS® Window continues to update in Freeze Frame. In addition, see the effects of menu setting changes with Instant Image Update. Pressing EXIT will exit Freeze Frame and the display will start to scroll. Freeze Frame is available in the Sonar, Sonar Zoom, and 200/83 kHz Split Sonar Views.

Bottom Presentation

As the boat moves, the unit charts the changes in depth on the display to create a profile of the Bottom Contour. The type of bottom can be determined from the return charted on the display. A Hard Bottom such as compacted sediment or flat rock appears as a thinner line across the display. A Soft Bottom such as mud or sand appears as a thicker line across the display. Rocky Bottoms have a broken, random appearance.

Bottom Contour Profile with RTS® Window.

The Narrow RTS® Window indicates the sonar intensity through the use of grayscale. The grayscale used matches the bottom view grayscale setting used in the sonar history window (i.e. Inverse, StructureID®, WhiteLine®, Bottom Black). The depth of the sonar return is indicated by the vertical placement of the return on the display depth scale.

The Wide RTS® Window in-

dicates the sonar intensity through the use of a bar graph. The length of the plotted return provides an indication of whether the return is weak or strong. The depth of the sonar return is indicated by the vertical placement of the return on the display depth scale. The Wide RTS® Window does not make use of grayscale.

Hard Bottom
Rocky Bottom	Soft Bottom

The sonar returns from the bottom, structure and fish can be represented as either Inverse (default), WhiteLine®, Structure ID®, or Bottom Black. See Sonar X-Press™ Menu: Bottom View for details on how to set the bottom view.

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