Basic Study of Hazardous Noxious Substance Detection Based On Hyperspectral Ground Experiment

Abstract

With an increase in international maritime traffic over time, ship accidents such as collisions, sinking, and oil leakages tend to occur more frequently. there has also been a recent steady increase in the number of hazardous noxious substance (HNS) spills. HNS materials are mostly composed of toxic materials, and their spills have a much more significant impact on marine resources and living organisms than general oil spills in the ocean. Thus, there is a need to completely understand the physical and chemical properties of HNSs. This can be achieved through establishing a library of spectral characteristics with respect to wavelengths from visible and near-infrared (VNIR) bands to shortwave infrared (SWIR) wavelengths. In this study, a ground HNS measurement experiment was conducted for artificially spilled HNS by using two hyperspectral cameras at VNIR and SWIR wavelengths. Representative HNSs such as styrene and toluene were spilled into an outdoor pool and their spectral characteristics were obtained. The relative ratio of HNS to seawater decreased and increased at 550 nm and showed different constant ratios at the SWIR wavelength. Noise removal and dimensional compression procedures were conducted by applying principal component analysis on HNS hyperspectral images. Pure HNS and seawater endmember spectra were extracted using four spectral mixture techniques N-FINDR, pixel purity index (PPI), independent component analysis (ICA), and vertex component analysis (VCA). The accuracy of detection values of styrene and toluene through the comparison of the abundance fraction were 99.42% and 99.56%, respectively. The results of this study are considered useful for HNS detection and the estimation of its extension area during in marine accidents by using hyperspectral remote sensing techniques