Simrad ARGUS FMCW 3G, User Manual

Page: 105 / 150

| 103
Tracking | Argus Radar Operator Manual
Minimum safety menu
This is a function for radar targets and AIS, which allows visualising and setting the threshold
of CPA and TCPA that defines when a target will be considered dangerous.
If for example, the values are set to 0.1 NM and 10 minutes (default values, re-set at every
start-up), when a target has a CPA of less than 0.1 NM and at the same time a TCPA of less
than 10 minutes, the “Danger Target Alarm” will be visualised. And if the audio is on, an audible
alarm will sound as well. Also the symbol of the target will change to a triangle and it will flash
in red color until the alarm is acknowledged by the operator.
Auto-Acquisition zone
This is a radar target and AIS function, which allows automatic
acquisition of all the echoes from radar and AIS targets entering
in a zone drawn around own ship. The Auto Acquisition Zone
is not stabilised, but always linked to own ship’s heading and it
rotates according to the heading movement (“Monitor Display
- General view” on page 22). Pressing the “Auto Acquisition
Zone” button, the following window will be visualised in the
Displaying Information Area (“Auto-Acquisition zone” on page
103).
At the same time, the shape of the Auto Acquisition area in the menu will be drawn on the
PPI in green color with dashed lines. There are 5 adjustable values:
•
Front range; the distance from the centre to the farther front point, or radius of the frontal arc
•
Width; the distance from the centre to the farther left or right point; note that the area is sym-
metric respect to its longitudinal axis
• Internal range; radius of the internal blank range. This value should be adjusted in order to
exclude the sea clutter
• Back range; radius of the back range
•
Back sector; angle in degrees of the back blind sector. This value should be adjusted to ex-
clude own ship wake or blind sector artefacts.
These values can be changed by means of the relative spin box to reach the desired propor-
tions of the shape. Obviously, some values are limited by others, for example the width cannot
be bigger than the front or back range, and the back range is limited to the back sector width.
Once the area on the PPI is drawn as desired, the Auto Acquisition Zone must be activated (by
means of the “Activate” button) and the “Accept” button must be pressed to store the zone in
the tracking program.
At this point, any radar echo or AIS target detected near the same position for 3 consecutive
scans within the Auto Acquisition Zone will automatically be acquired and the alarm “RADAR
TRACKED TARGET AUTO ACQUIRED” or “AIS TARGET AUTO ACQUIRED” is activated. The target
symbols are visualised in “Tracking target symbols” on page 93 (and AIS Target).
¼
Note: The “ACCEPT” button and the “X” window execute the same function.
Guard zones/Auto Acquisition zones
The Guard Zone is a radar target and AIS function for generating a warning when a target
passes through an area. That area is called Guard Zone or Guard Ring, due to the fact that its
similar to a sector of a ring, it is geometrically the intersection between two concentric circu-
lar sectors, centred on own ship position. The farther side area can be from 0.4 NM to 24 NM
and a thickness of 0.5 NM. The angle of the sector cannot be lower than 5° or more that 359°.
The type of zone can be switched between “Guard zone” and “Auto Acquisition Zone”.
When Auto Acquisition is chosen, its drawn in green color and it has the same behaviour of
the ones described in the previous sub-paragraph.