A template representing a desired target is applied to response signals
from an area including a plurality of targets and illuminated by
electromagnetic radiation. The response signals include poles or damped
sinusoids representing resonances (e.g., resonant frequencies) distinctly
associated with each of the targets within the area. An embodiment of the
present invention utilizes pole or damped sinusoid frequencies of a
desired target to construct the template or comb-like pattern that is
compared to the mixture of pole frequencies within the response signals
from the area. The comparison yields a resulting score that indicates the
presence of the desired target within the area.