A method for discriminating between explosive events having their origins
in High Explosive or Chemical/Biological detonation employing
multiresolution analysis provided by a discrete wavelet transform.
Original signatures of explosive events are broken down into subband
components thereby removing higher frequency noise features and creating
two sets of coefficients at varying levels of decomposition. These
coefficients are obtained each time the signal is passed through a
lowpass and highpass filter bank whose impulse response is derived from
Daubechies db5 wavelet. Distinct features are obtained through the
process of isolating the details of the high oscillatory components of
the signature. The ratio of energy contained within the details at
varying levels of decomposition is sufficient to discriminate between
explosive events such as High Explosive and Chemical/Biological.