Simrad GO XSE Operator's Manual page 105

Head-up
In Head-up mode the heading line on the PPI is oriented on the 0°
on the bearing scale and towards the top of the screen. The radar
image is displayed relative to own ship, and when the ship turns the
radar image rotates.
Ú Note:
Head-up is only available in Relative motion mode, and it
is the only orientation mode available if the radar is not
connected to a heading source.
North up
In North up mode the 0° indication on the PPI represents north. The
heading line on the PPI is oriented according to own ship heading
obtained from the gyro compass. When the ship turns the heading
line changes its direction according to the ship's heading, while the
radar image remains stabilized.
The North up orientation is not available if no heading source is
connected to the radar. If heading data is lost, the system will
automatically switch to Head-up orientation.
Course up
In Course up mode, the top of the bearing scale indicates the ship's
true course measured from north at the time Course up was
activated. When the ship turns the bearing scale remains fixed,
while the heading line rotates with the ship's yawing and course
change.
The Course up orientation is reset by re-selecting the Course up
mode.
Radar motion mode
Radar motion is indicated on the upper left corner of the radar panel
as either TM (True motion) or RM (Relative motion).
Relative motion
In Relative motion your vessel remains in a fixed location on the
Radar PPI, and all other objects move relative to your position.
You select the position of the fixed location as described in "Offsetting
the PPI center" on page 106.
Radar | GO XSE Operator Manual
105