Raymarine L1250D, Owner'S Handbook Manual

Page: 119 / 246

Chapter 5: Adjusting the Display 5-19
Usi
ng A
-S
cop
e
Using A-Scope
The scrolling bottom display provides a historical record of sonar echoes. Use
the A-Scope screen to show raw sonar data directly from the transducer beam.
This gives you a “real time” image of fish and bottom structure directly below
the transducer. This function is very useful in showing the strength of the echo
returned from a fish. At the lower end of the window, A-Scope also displays
the patented Bottom Coverage width indication.
➤
To display the A-Scope image:
1. Press the
A-SCOPE
soft key. The display is split vertically, with the A-Scope
image in the right hand window and the scrolling bottom image in the left
hand window.
2. Press the
A-SCOPE MODE
soft key to select one of the three modes for
A-Scope, as demonstrated in Figure 5-8 :
i. Mode 1, in which the A-Scope image is angled outward as the signal
width (indicated with dotted lines) increases with depth.
ii. Mode 2, in which the image expands to take up the entire A-Scope win-
dow, providing greater resolution.
iii. Mode 3, in which only the left hand side of the image displayed in Mode
2 expands to the entire A-Scope window. This mode provides the great-
est resolution.
3. Press
ENTER
to accept your selection.
Note: If the Bottom Lock or Zoom image is displayed, selecting A-Scope auto-
matically switches
OFF
Bottom Lock and Zoom.
If you have split frequency selected, the A-Scope image is displayed in both
frequency windows.
➤
To remove the A-Scope image:
1. Press the
A-SCOPE soft key.
2. Press the
A-SCOPE ON OFF
soft key to toggle off A-Scope.
3. Press
ENTER
.
A-SCOPE
A-SCOPE
MODE
1 2 3
A-SCOPE
OFF ON
81213_1.book Page 19 Monday, March 17, 2003 1:14 PM