Area correlation tracking (ACT) is an effective solution for tracking targets that have neither prominent features nor high contrast with the background. The essential step in area correlation tracking is to find the position of best-fit between the reference image of the terrain surrounding the desired target to the real-time scene acquired by an imaging sensor. The image matching is accomplished by the basic mathematical correlation coefficient algorithm (CCA) or mean absolute difference (MAD) algorithm or other algorithms derived from these algorithms. The reference image has to be updated very frequently to circumvent the problems associated with image growth, aspect changes, rotation, etc. Otherwise the image tracking algorithm may become divergent with time thereby losing the track. This paper addresses the real-time implementation of area correlation algorithms for an on-board application. The implementation poses challenges because of the very large number of integer multiplications required by the correlation coefficient algorithm. In view of the space and power constraints in on board applications, the realization becomes all the more complex. To realize the system, a parallel pipelines architecture is adapted. Very high speed arithmetic devices are used for computations, programmable logic devices for the high speed control and a dual microprocessor based system for overall control. This hardware has been evaluated by integrating with a full fledged imaging seeker in captive flight trials. The results are presented.

Date Published: 25 November 1992
PDF: 11 pages
Proc. SPIE 1697, Acquisition, Tracking, and Pointing VI, (25 November 1992); doi: 10.1117/12.138173

Published in SPIE Proceedings Vol. 1697:
Acquisition, Tracking, and Pointing VI
Michael K. Masten; Larry A. Stockum, Editor(s)