Biological sample evaluation using a line-scan based SWIR hyperspectral imaging system

Authors: HONG, SEOK - Us Forest Service (FS); LEE, HOONSOO - Us Forest Service (FS); BAEK, INSUCK - University Of Maryland; OH, MIRAE - Us Forest Service (FS); Kim, Moon

Submitted to: ASABE Annual International Meeting
Publication Type: Proceedings
Publication Acceptance Date: 6/8/2016
Publication Date: 7/30/2016
Citation: Hong, S.M., Lee, H., Baek, I., Oh, M., Kim, M.S. 2016. Biological sample evaluation using a line-scan based SWIR hyperspectral imaging system. ASABE Annual International Meeting, St. Joseph, MI. ASABE Paper No. 162461739.

Interpretive Summary: Researchers developed a new line-scan hyperspectral imaging system to acquire shortwave infrared (SWIR) images for biological sample evaluation. The system uses a mercury-cadmium-telluride focal plane array detector, which extends the effective spectral imaging region beyond the 400 – 1000 nm and 900 – 1700 nm regions that are typically imaged by systems using more common silicon-based CCD cameras and Indium-Gallium-Arsenide CCD cameras, respectively. Previously, agricultural applications of infrared imaging were limited to near-infrared wavelengths up to 1700 nm; the new system extends infrared imaging from 900 to 2500 nm. This paper provides a detailed description of the newly developed SWIR system, and also presents preliminary results from analysis of hyperspectral SWIR images of dry milk-melamine mixtures to select wavebands for a two-waveband ratio algorithm to detect melamine present in milk-melamine mixtures of various concentrations. This research will benefit the food processing industry and regulatory agencies, as well as researchers in academia, government, and industry interested in non-destructive methods for food inspection, contaminant detection, and ingredient authentication.

Technical Abstract: A new line-scan hyperspectral imaging system was developed to enable short wavelength infrared (SWIR) imagery for biological sample evaluation. Critical sensing components include a SWIR imaging spectrograph and an HgCdTe (MCT) focal plane array detector. To date, agricultural applications of infrared hyperspectral imaging have been limited to the near-infrared spectral region up to 1700 nm. This new SWIR hyperspectral imaging system has extended the hyperspectral reflectance imaging capabilities up to 2500 nm for nondestructive evaluation of biological samples. This paper provides a detailed description of the newly developed SWIR hyperspectral imaging system. In addition, preliminary results for detection of melamine in milk powders using the new SWIR hyperspectral imaging system and a band ratio algorithm are presented.