Definitions of terms to be used in connection with ARPA performance IMO standards
|Heading||means the direction in which the bows of a ship are pointing expressed as an angular displacemement from north.|
|Targetʼs predicted Motion
||means a prediction of future target motion based on linear extrapolation from its present motion as determined by past measurements of its range and bearing on the radar.|
|Relative Vector||means the predicted movement of a target relative to own ship.|
||means the predicted true motion of a target as a result of own ship`s direction and speed input. The true vector may be either displayed with reference to the water or to the ground.
|Acquisition||means the process of selecting a target or targets and initiang their tracking.|
|Tracking||means the computer process of observing the sequential changes in the position of a target in order to establish its motion.|
|Target Swoop||means a situation in which the incoming radar data for a tracked target becomes incorrectly associated with another tracked target or a non-tracked radar echo.|
||means an arena set up by the observer which should automatically acquire a target when it enters such an area.|
||means equally time-space past position of a target, which is being tracked. The history may be relative or true.
||means tracks displayed by the radar echoes of targets in the form of a synthetic afterglow. The trails may be either relative or true. The true trails may be sea or grounded stabilised.