Optical systems based on rotating reticles were invented to determine the p
olar coordinates of a primarily IR optical source. Such systems fail when s
everal optical sources are present in their field of view simultaneously. I
t is demonstrated experimentally that this drawback can be overcome by the
application of a blind-signal-separation algorithm on the output signals of
a modified optical system. The separation of the modified optical system r
esponses into independent components yields modulating functions that carry
information concerning the polar coordinates of the corresponding single o
ptical sources. (C) 1999 Optical Society of America.