Furuno FAR-2107(-BB) - Manual (Page 71)

1. RADAR OPERATION
1-49
1.30.4 Saving, copying target trails
By turning on the functions TRAIL RESTART and TRAIL COPY, you may
continue painting target trails whenever the range scale is changed. The amount
of range change determines how the radar paints trails. See the table below for
details. Note however that if the previous range is restored within 10 seconds
and the amount of range change is within 1/3, trails continue as before.
If trails become difficult to view, you may delete them. For details, see section
1.30.10.
Amount of range change
How trails are processed
Large (ex. 3 nm→12 nm) Trails continue on targets that were within the
previous range scale. Trails are not initiated for
targets that were not within the previous range.
Within 1/3 of previous range
(ex. 3 nm→1.5 nm) Trails continue on targets that were in the
previous range scale.
Within 1/4 of previous range
(ex. 3 nm→0.75 nm) Trails are restarted.
(a) Previous range (b) New range
No trail generated
for target not within
previous range
1. Right-click the TRAIL MODE box to display the TRAIL menu.
2. Select 5 TRAIL RESTART.
3. Select ON or OFF as appropriate.
ON: Trails start extending on the newly selected range.
OFF: Trails extend only on the range where they were initiated.
4. Select 6 TRAIL COPY.
5. Select ON or OFF as appropriate.
6. Push the right button to close the menu.