Simrad ARGUS FMCW 3G, User Manual

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Radar presentation and video processing | Argus Radar Operator Manual
North Up
Operating in North Up mode, the heading line on
the PPI is oriented according to own ship heading
obtained from the Gyro compass, the 0° indication on
the PPI represents North. When own ship turns, the
heading line changes its direction according to the
ship’s heading and the radar image remains stabi-
lised in azimuth. The target echo is visualised at its
measured distance and in the true compass direction
from own ship. The North Up orientation mode is not
available if no heading source is connected to the
radar. If heading data is lost, the system will automati-
cally switch to Head Up.
Course Up
When this mode is selected, own ship course is oriented to 0°; when own ship turns, the sys-
tem maintains the orientation of the picture rotating the heading line, to avoid whitening the
sector between the initial and the terminal position. It is possible to be orientated to the new
course by pressing the “Reset Course” button.
Relative motion (RM)
Own ship remains fixed on the PPI, and the radar image moves around it with relative motion.
True motion (TM)
Own ship position moves across the PPI according to own ship’s course and speed, while the
radar image is displayed according to its true movement (land is steady and other ships are
moving). If own ship position exceeds 50% off-centre on the PPI, its position is automatically
reset to a point of 50% radius in the opposite direction. If heading data is lost, the presenta-
tion mode is changed to Head-Up mode and the North marker disappears.
P reset/TM reset
The function of the Presentation Reset button (“Orientation and motion modes” on page
61) is to reset own ship position in the PPI. Depending if the system is operating in True or
in Relative Motion, the button is labelled “TM Reset” or “P Reset”. The function of the button is
the same in both conditions: pressing the button, the PPI will be Off-centered and own ship
symbol will be placed as far as possible from the point where it would disappear (opposite
side respect to its course, at 50% of the range scale from the PPI centre), as shown in the fol-
lowing figures:
Own ship crossing the Off-centre limit of 50% Own ship position after the TM reset
This operation is therefore automatically performed by the system when, in True Motion, own
ship passes 50% of the range scale from the PPI centre. In the above figures the 50% limit is
represented by the red circle. Note, that the red circle is not visible on the PPI, but has been
drawn in the above figures to better explain how True Motion Reset works.