Patent ID: 7333897

Claim:
A method for determining a most likely material composition of an object, the method comprising: storing, for at least one material composition, at least one respective stored radiation polarization transformation at a plurality of wavelengths for each of the material compositions within the at least one material composition; receiving a received signal, the received signal corresponding to a transmitted electromagnetic signal that was transmitted by a transmitter towards an object, the transmitted electromagnetic signal having a known transmitted polarization profile; determining a respective received polarization for each of at least one wavelength of the received signal that has encountered the object, the received signal comprising a portion of the transmitted electromagnetic signal that has encountered the object; determining, for each of the at least one wavelength, at least one calculated polarization transformation based upon at least one polarization trajectory between the transmitted polarization profile and the respective received polarization for at least one of the at least one wavelength of the received signal; comparing, for each of the at least one wavelength, the respective calculated polarization transformations to the at least one respective stored radiation polarization transformations for at least one of the plurality of material compositions; estimating, based on the comparing, a most likely material composition for the object; and outputting an indication of the most likely material composition.