User's Manual

Table Of Contents
NACOS Platinum
ED 3100 G 140 / 04 (2011-11)
Operating Instructions
III-3 Permanent Area for Navigation
III Main Applications.fm / 10.11.11
III-52
3.3.3 Trails
For radar echoes moving on the PPI, video trails can be displayed. These trails can be
used as synthetic afterglow of the target video. Trails are generated from previous
antenna scans and can be varied as follows:
- The display of trails can be switched on and off.
- Their length can be specified.
- If the screen stabilisation is set to Rel. Motion, the trails can be displayed with
the PPI/chart area orientation North-Up and Course-Up relative to own ship or
with true (absolute) orientation, i.e. in relation to the sea bottom or water stabi-
lized.
- The trail history can be deleted so that they have to build up again
by the setting Off in the menu and selecting the time again
• by a MORE click into the PPI and selecting Clear Trails
In the true display mode, trails make it possible to reach a conclusion quickly about the manoeuvre
performed by radar targets. In the relative display, the trails provide a quick overview of the danger situ-
ation (a constant bearing can quickly be recognized). However, only qualitative information can be
obtained from them.
Switching the Display of the Trails On and Off
The display of the trails is switched on and off by clicking on the Trails field.
Specifying the Length of the Trails
Click on the Trails field with the MORE key; then, in the dialog that is opened as a result, click on the
desired time
In the Trails field, the length currently being selected is indicated, i.e. the max. length of the trails on
the PPI.
Switching the Trails to Relative or True Display
The switch-over is performed by clicking into the Relative/True field in the Vectors & Trails group.
This selection is then also valid for target vectors and their past plots.
Deletion of Trails
Click on the PPI area with the MORE key. In the dialog that is opened as a result, click Clear Trails
with the DO key.
The trails are also deleted whenever a switch-over occurs which changes the entire radar video
transceiver selection or range, but they then appear again and build up over time.
If the trails are lengthened, they reach the new specified length only after the time differ-
ence (i.e. in the case of switching over from 4 to 12 minutes, 8 minutes will pass before
the trails correspond to a length of 12 minutes).
The reduction of the trail length too takes some time.