Radar cross-section 
Radar cross-section of a target determines the power density returned 
to the radar for a particular power density incident on the target 
 
 
Range Rings 
A set of concentric circles labeled by distance from CCRP. 
 
 
Reference target 
A symbol indicating that the associated tracked stationary target    is 
used as a speed reference for the ground stabilization 
 
 
Relative course 
The direction of motion of a target relative to own ship motion 
 
 
Relative speed 
The speed of a target relative to own ship’s speed data 
 
 
Relative vector   
A predicted movement of a target relative to own ship’s motion 
 
 
RM 
Relative Motion 
A display on which the position of own ship remains fixed, and all 
targets move relative to own ship. 
 
 
RM(R) 
Relative Motion.  Relative Trails. 
 
 
RM(T) 
Relative Motion.  True Trails. 
 
 
ROT 
Rate Of Turn 
Change of heading per time unit. 
 
 
Route 
A set of waypoints. 
 
 
RR 
Range Rings 
S 
SART 
Search And Rescue Transponder 
Radar transponder capable of operating in the 9GHz band 
 
 
Sea stabilization 
A display mode in which speed and course information are referred to 
the sea. 
 
 
Sea state 
Status of the sea condition due to the weather environment, expressed 
as a sea state 0 for flat conditions with minimal wind, to sea state 8 
for very rough sea conditions. 
 
 
SET 
The current direction for manual correction or the current speed on 
the horizontal axis of the 2-axis log is displayed. 
 
 
Sleeping AIS target 
A target indicating the presence and orientation of a vessel equipped 
with AIS in a certain location. 
 
 
- xx -