sample spectra of mines and clutter


The strongest discriminant of the plastic mines is a large bump in the 1-2 kHz range
coupled with a weak spectrum at higher frequencies.  The box mine exhibits multiple
flexing resonances of its thin walls, which however are easily damped when the mine
is buried in hard soil.  Hard objects (rock, metal, glass) show large resonances
above 3 kHz.  The softer objects show no significant modes.

russian pmn mine -- receiver operating characteristic