1. A method performed by processing circuitry and memory configured for determining if a physical target is formed from a candidate material, comprising: receiving a first image of the physical target acquire first acquisition angle; delineating the physical target within the first image as a first area; extracting a first spectral radiance value from the first area; receiving a second image of the physical target acquired at a second acquisition angle different from the first acquisition angle; delineating the physical target within the second image as a second area; extracting a second spectral radiance value from the second area; evaluating an estimated target spectral signature for the physical target based at least in part on the first and second spectral radiance values; calculating a predicted candidate spectral signature for the candidate material based at least in part on the first and second acquisition angles; calculating a correlation statistic that correlates the predicted candidate spectral signature to the estimate target spectral signature; comparing the correlation statistic to a predetermined probability threshold; and determining from the comparison that the physical target is formed from the candidate material.