Marine Radar Guides
What is a Radar and why do I need one?
An acronym coined from the science of RAdio Detection And Ranging, radar is a
system that uses electromagnetic waves to identify the range, altitude,
direction or speed of moving and fixed objects, including ships, aircraft,
weather formations and terrain. A radar unit has a transmitter that emits
microwaves which reflect off targets within a given radius and return signals
that can be amplified to create a visual representation of their presence on a
screen.
Radar is employed in a wide range of situations, including maritime, aviation
and defense. In the marine context radar is regarded as an essential
instrument, not just for large ships but for vessels of all sizes and
descriptions in the racing, leisure, commercial and naval sectors. Radar
enables the host vessel to see a full 360-degree display of what often cannot
be seen with the naked eye, particularly in darkness or conditions of poor
visibility.
The range and level of detail provided by a radar set depends on its power and
the height at which it is mounted, as conventional systems work on a
line-of-sight basis. A modern radar detects the presence of an object and
calculates its speed of travel by calculating the time-lapse between echo
returns and plotting these on the screen so that the user can monitor traffic
and other objects in real-time and in relation to the host position, giving
all-round visibility in all conditions and up to great distances. Radar
returns are usually colour-coded: from blue or green for weak returns, to red
or magenta for very strong returns. This is why a thunderstorm, for example,
is depicted on meteorological radar in bright red.
Radar units are often integrated with GPS chartplotters to overlay a dynamic
view of the external environment on a static chart of physical and
navigational objects.
Dual Range mode
The dual range mode will enable the helmsman to see his immediate
area while simultaneously keeping a watchful eye on what is approaching in the
distance. Viewing two ranges on one split screen allows, for example, both
0.5NM and 6NM to be selected, which provides the helmsman with a view of his
immediate proximity in detail, together with approaching hazards in the
distance. This is a major contribution towards the safety of vessels at sea,
especially for vessels that do not have two radars fitted.
Night Display
During the hours of darkness the radar can be adjusted to reverse the
contrast of the display. This is an important safety feature that reduces
light emission from the screen, while accentuating targets and providing
continuity of the helmsman’s night vision
Color Presentation of Targets
Target echoes are presented in different colors depending on the
strength. This is useful in rough conditions to spot smaller targets.
High Speed Update
By using a high speed antenna rotation the update rate of the radar
image is doubled. This benefits high speed craft by increasing the target
update rate and enabling the dual range function, thereby allowing early
detection and tracking of high speed radar targets. This is important with the
increasing speed of today’s vessels at sea.
Semi 3D Facility
The semi 3D facility is particularly valuable for targets to be seen
clearly and naturally for easy recognition. Semi-3D gives a presentation of
weak and strong echoes in 3D, ideal for entering narrow passages or harbors.
By connecting an electronic compass and speed log to the radar via the option
input, the true motion function can be selected.
Split Screen
The radar shows a simultaneous split screen of both conventional and
3D displays.
Automatic Tracing Aid
Automatic Tracking Aid (ATA) which tracks up to 10 targets designated
by the user. Once locked-on, the Radar will automatically provide a menu of
data which includes speed, bearing, course and closest point of approach on
all targets selected. A built-in alarm system warns of possible collision or
lost target, making watch-keeping easier and safer.
Echo Tracking
Indicates motion of radar targets relative to your vessel. Adjustable
echo trail lengths enable different levels of observation of other ships
movements when in true motion. The tracking duration can be selected in steps,
from 15 seconds up to 6 minutes, or continuous.
|