What do you understand by Spoking & Starring?
Spoking
This is the name given to unwanted radial lines that sometimes appear on the screen. These ‘spokes’ may occur all round the screen or may be confined to certain areas only. They may appear on every rotation of the trace or they may appear intermittently. They may be complete or incomplete radial lines.
The presence of faults such as dirty contacts, either of the heading marker circuit at the scanner or of the slip rings of the rotating deflection coils, are common causes of spoking. Spoking can also be caused by heavy sparking of motors, etc., of other instruments nearby, such as those of clear-view screens, echo sounders, etc.
Starring
Echoes sometimes appear on the screen in the form of curves or spirals of dotted lines, as shown in the above figure, which change position with every rotation of the scanner. This effect is called starring and is caused by another ship’s radar, whose transmitting frequency is within the bandwidth of the own ship’s radar, operating in the vicinity.
