39
User Manual
5.19 Is a gyrocompass or flux gate compass better?
The gyrocompass it is a better choice because it is faster but it is much more
expensive. The flux gate compass is slower but it is much cheaper. Using a flux-
gate you have to expect to see delays in the rotation of the chart when in Chart
Overlay mode.
5.20 How can I be advised of potential dangers for the
navigation?
Use the Guard Zone alarms.
5.21 What are Guard Zones?
Guard Zones are areas defined by the user that causes an audible and visual
alarm to be triggered when a target exceeding a certain density enters into it. The
density of the target that may trigger the alarm is regulated by mean of the
Guard Zone sensitivity. There are of two types of Guard Zones: Circular or Secto-
rial. They are fixed with respect to the ship position and heading but their range
and orientation (only for sector type) are user defined.
5.22 How should I set the Guard Zone sensitivity?
Guard Zone sensitivity must be regulated accordingly to the current Gain of the
Radar. The higher the sensitivity the smaller the target that may trigger the alarm.
In general if you regulated your Radar to obtain a clean picture you can set the
Guard Zone sensitivity very high to detect even the smaller targets. When clutter
is present in the Radar picture due to a high gain setting, you'll have to reduce the
Guard Zone sensitivity to avoid triggering false alarms. In general a way to set
the maximum sensitivity for a Guard Zone is to start increasing the sensitivity
until an alarm is triggered and then reduce the sensitivity until the alarm stops.
5.23 What is the STC, and how should I operate it?
STC is the Sensitivity Time Constant. It is used to reduce the sensitivity and thus
the clutter in the ranges closer to the Radar. Operate the STC to reduce the
echoes coming from the closer ranges to an acceptable range.
5.24 What is the FTC and how should I operate it?
FTC is the Fast Time Constant. It is used to reduce the echoes coming from large
objects that can hide other small objects. It is also called the rain control since it
is capable of reducing the effects of the rain on the display.
5.25 What is the MBS?
The MBS is the Main Bang Suppression. It is used to suppress the stronger echoes
caused by Radar transmission in the receiver. It is similar to STC but its operates
in a shorter range.
