GLOSSARY 
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NSK North Stabilization Kit
 
 
N-UP North up 
The north is always pointed to the top center of the radar 
displa
y. 
 
O
 
Own track  Display function of own ship’s track 
 
Open Array Antenna  An antenna consisting of arrayed antenna elements, covered with a radome, and rotating 
itself. 
 
 
P
 
PI Parallel Index line
 
 
Past positions  Equally time-spaced past position marks of a tracked or AIS target and own ship. 
 
POSN Position 
 
PRF Pulse Repetition Frequency 
The number of radar pulses transmitted each second. 
 
PROC Process 
Radar signal processing function 
 
R
 
Radar   Acronym for RAdio Detection And Ranging 
 
Radar beacon  A navigation aid which responds to the radar transmission by generating a radar signal to identify 
its position and identity 
 
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 
 
SBAS Satellite-Based Augmentation System 
                         Generic technique for correcting the error of the GPS using the geostationary satellite   
  This is used for the positioning accuracy of GPS higher. 
 
Sea stabilization  A display mode in which speed and course information are referred to the sea.