Tracking
This section provides a description of the range of functions, which Octec can apply to the real time processing of video images.
Centroid Track
Centroid tracking is used for tracking bounded objects such as an aircraft, which can be fully contained within the track window. Centroid tracking normally uses either the Centroid or MTT algorithms in Target Acquisition mode since both these algorithms initialise the track window position and size to enclose a target on entry to Autotrack mode. MTT will generally give better results since it is capable of designating a single object in the presence of other clutter. Centroid will give a better result when the target is fragmented.
MTT (Multiple Target Track)
MTT is used for tracking bounded objects such as aircraft or ground vehicles that are fully contained within the track window. The MTT gives good performance with small targets in high clutter.
Correlation
Correlation can be used for tracking many types of object but is most effective when tracking unbounded targets that have low dynamics. Typically this would be objects at close range which extend outside of the sensor field of view such as a ship.
Correlation tracking normally also uses either the Correlation algorithm in Target Acquisition mode. In this case the track window is initialised to the acquisition window position and size on entry to Autotrack mode. Therefore in this mode it is important that the acquisition window is sized so that the target area fills the whole window. It is possible to re-size the window during Autotrack mode and this is often advisable as the target range changes.
Correlation tracking can also use the other tracking algorithms (Centroid, MTT and Edge) in Target Acquisition mode. In this case the track window is initialised to a specific point (Target centre or target edge) on the target on entry to Autotrack mode.
Phase Correlation
The phase correlation algorithm is a very general purpose algorithm that can be used for tracking both un-bounded objects and bounded moving objects within the image. The algorithm can give good results when tracking bounded moving targets in high clutter such as tracking ground vehicles from an airborne platform.
Phase Correlation tracking can use any of the track algorithms (Centroid, Correlation, MTT and Edge) in Target Acquisition mode. In this case the track window is initialised to either window centre, target centre or target edge on entry to Autotrack mode depending on the selected algorithm in acquisition mode.
Combined
The phase correlation algorithm is a very general-purpose algorithm that can be used for tracking both un-bounded objects and bounded moving objects within the image. The algorithm can give good results when tracking bounded moving targets in high clutter such as tracking ground vehicles from an airborne platform.
Combined tracking normally uses either the Centroid or MTT algorithms in Target Acquisition mode since both these algorithms initialise the track window position and size to enclose a target on entry to Autotrack mode. MTT will generally give better results since it is capable of designating a single object in the presence of other clutter. Centroid will give a better result when the target is fragmented.
SceneLock
The SceneLock algorithm tracks a number of points in the scene and then combines the motion estimates of each point to estimate the overall scene motion. The allocation and selection of tracking points in the scene occurs automatically. When existing tracking points move outside of the field of view, new tracking points are automatically identified and assigned. The aim point is initialised to the point in the scene, which is located at the boresight when tracking is initiated. The SceneLock then continues to track and report the position of this point in the scene. The symbology uses a cross to indicate the SceneLock aimpoint