Comparison of fast correlation algorithms for target tracking
Laser Aided Detection and Ranging (LADAR) imaging systems can be used to provide high resolution
imaging and tracking of moving targets at night. Central to the tracking system is a high speed correlation
algorithm to determine target motion between sensor image frames. Several issues complicate the
correlation calculations. These include coherent speckle noise and atmosphere induced scintillation of the
illuminator beam. The Fitts correlation algorithm is commonly used because of its simplicity and speed.
However it is only optimal when the shift between sensor frames is less than a pixel. In addition it can be
sensitive to certain types of noise. Projection based phase only (PBPO) is another type of correlation
algorithm that is also high speed and in many cases less sensitive to noise. In this paper we compare the
Fitts algorithm with PBPO in terms of number of computations and noise immunity when used in a
LADAR tracker.