Efficacy of Hyperspectral Imaging in Identifying Latent Trace Signatures

Sarah Mosinski* and Jacqueline Speir

Department of Forensic and Investigative Science, West Virginia University, Morgantown, WV 26505

Presentation Category: Physical Sciences & Engineering (Poster Presentation #160)

Student’s Major: Forensic Chemistry

Interactions between electromagnetic radiation and matter can be harnessed as a means of gathering quantitative and qualitative information about a target. Hyperspectral Imaging (HSI) is a subcategory of spectral imaging that combines spectroscopy and digital imaging with the aim of collecting spatial and spectral information for complex scenes. Unlike traditional RGB cameras - which earned the RGB moniker because they can be used to generate three-color channel images (red, green and blue) - HSI can divide a larger swath of the electromagnetic spectrum into smaller spectral samples. This process generates a datacube comprised of 100’s of channels, with a resulting increased spectral resolution. The focus of this study was to test the efficacy of HSI in a forensic setting for the purposes of identifying latent trace signatures. Research into this topic required the completion of three major objectives. First, spectral reference databases consisting of blood, wood, paints, and tile were captured. Second, orthogonal subspace projection (OSP) was employed as a means of spectral unmixing. Finally, a double-blind experiment was conducted to test the overall efficacy of HSI and OSP at identifying the presence of unknown and latent trace signatures. Preliminary results indicate that the technique can identify blood targets at an abundance as low as 25%, with the overall success varying as a function of the background interference.

Funding:

Program/mechanism supporting research/creative efforts: WVU's Research Apprenticeship Program (RAP) & accompanying HONR 297-level course