1. A material detection system comprising: an electromagnetic (EM) sensor system configured to collect radiation from a region of interest; and a processing unit configured to measure reflectivity data associated with a material of interest in the region of interest based on the collected radiation and to calculate a refractive index of the material of interest based on the measured reflectivity data, the processing unit being further configured to identify the material of interest based on the refractive index of the material of interest.