Raymarine L470 instruction manual A-Scope Bottom Coverage Mode, Operating Instructions

A-Scope (Bottom Coverage) Mode

Fig. 3-14

A-Scope Mode

(half screen)

NormalA-Scope

displaydisplay

A-Scope image (real time image)

Fish indication

Bottom coverage

On the FishFinder Page the bottom graph is “drawn” after the FishFinder receives several echoes. This has the effect of showing a record of the bottom contour. The A-scope Mode shows raw sonar data directly from the transducer beam. This gives you a “real time” image of fish and bottom structure directly below the transducer. (The A-Scope Mode is sometimes called an “In-Line Flasher.”) This function is very useful in showing the strength of the echo returned from a fish.

You can reach the A-Scope Mode at any time by pressing the A-Scope button. Figure 3-14. The left section of the A-Scope Mode shows a section of the normal FishFinder Page. The right section shows the A- Scope image.

A-Scope image

The normal FishFinder Page with the White Line feature enabled (see Fig. 3-4) allows you to tell the difference between two levels of echo strength. Weak targets are shown in black, while strong targets are shown in a gray checkered pattern. The A-Scope image, by contrast, gives you more detailed information. In the A-Scope Mode, stronger echoes

52 Operating Instructions