  In radio-based physics experiments, sensitive analysis techniques are often
required to extract signals at or below the level of noise. For a recent
experiment at the SLAC National Accelerator Laboratory to test a radar-based
detection scheme for high energy neutrino cascades, such a sensitive analysis
was employed to dig down into a spurious background and extract a putative
signal. In this technique, the backgrounds are decomposed into an orthonormal
basis, into which individual data vectors (signal + background) can be
expanded. This expansion is a filter that can extract signals with amplitudes
$\sim$1 % of the background. This analysis technique is particularly useful for
applications when the exact signal characteristics (spectral content, duration)
are not known. In this proceeding we briefly present the results of this
analysis in the context of test-beam experiment 576 (T576) at SLAC.
