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The Air Force Institute of Technology's Center for Directed Energy's (AFIT/CDE), under sponsorship of the HEL Joint
Technology Office, and as part of a multidisciplinary research initiative on aero optics effects, has designed and
fabricated a laser pointing/tracking system. This system will serve as the laser source for a series of in-flight data
collection campaigns involving two aircraft.
Real-Time tracking systems have a distinct difference from automatic image analysis. Both activities often involve the
segmentation of an image and the automatic location of an item of interest. A number of advanced tracking algorithms
have been developed for applications involving processing previously captured data. Medical imaging applications
frequently use post processing algorithms to segment anomalies in medical imaging.
In this paper we discuss an airborne laser pointing and tracking system and its requirements, designed and implemented
at AFIT. This application is different because the image processing must be completed during the inter-frame period.
AFIT analyzed available tracking algorithms including: centroid tracking, Fitts correlator, Posterior Track, and Active
Contour. These algorithms were evaluated on their ability to both accurately track and to be computed in real time using
existing hardware.
The analysis shows that some of the more accurate tracking algorithms are not easily implementable in real time. Often
there are large numbers of correlations that must be computed for each frame. Higher resolution images quickly escalate
this problem. Algorithm selection for tracking applications must balance the need for accuracy and computational
simplicity.
Real time tracking algorithms are limited by the amount of time between frames with which to processes the data.
Specialized hardware can improve this situation. We selected centroid tracking for the airborne application and evaluate
its performance to show that it meets design requirements.
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