JRC JMA-2353 Instruction Manual page 64

Chapter 2 OPERATIONS
2.7 SOFT KEY OPERATION
2 Operate with the soft keys.
Soft key 1: REF Level1
Selects a radar video level required for plotting radar trails.
"REF Level1" is the lowest level while "REF Level4" is the highest level.
 When radar trails are plotted with unwanted waves, change to a higher level.
 To thin radar trails, change to a higher level.
 If radar trails are plotted in snatches, change to a lower level.
Soft key 2: Time/Cont Off
This function superimpose-displays time radar trails and continuous radar trails.
When "Time/Cont Off" is selected, this superimpose-display is disabled.
When "Time/Cont On" is selected, this superimpose-display is enabled.
Soft key 3: True
Switches the radar trail display between true and relative motion trail modes.
Reference:
True bearing signal input and speed signal input are required to display radar trails in true
motion trail mode.
Soft key 4: Trails
When "RADAR Trails" of the soft key menu is selected, "Trails" of the soft key
display is color-inverted.
Turn the [MULTI] control to change the radar trail length.
2-30
REF Level2
Relative
True motion trails:
The system plots the absolute motion trails of a target, irrespective of
the own ship's position.
The operator can easily judge the course and speed of the target.
The system does not plot the trails of land and other fixed targets.
Relative motion trails:
The system plots the trails of a target at a position relative to the own
ship.
The operator can easily judge whether the target is approaching the
own ship.
While the own ship is moving, the system also plots the trails when the
own ship is turning.
REF Level3
Time/Cont On
REF Level4