

Tis' only a gleam in my eye at this point.  I have yet to chose a tracking 
method.  The initial requirement was to design a system to locate a dancer
in one of eight zones across the stage.  I did some experiments with 
pyroelectric detectors and found them difficult to align to get a definite
zone transition.  And dancers stand still alot, so their IR signature goes
away.  The good thing about pryoelectrics is that their signal is proportional 
to the size of the warm body (or body part), and the velocity of said body.
This could be useful for detecting the intensity of a dance gesture.

Dancers also really hate to wear little boxes and batteries strapped on their 
bodies, but they really need to be emitting some kind of signal to be tracked.