Remote Identification of Liquid Surface Contamination by ImagingFourier Transform Spectrometry

摘要

Imaging Fourier transform spectrometry (FTS) was applied to remotely identify liquids on various surfaces. The spectraare dependent on the liquid film (composition and dimensions), the background surface and the illumination (artificialsource or radiation from the sky). A radiative transfer model was applied to calculate spectra of the liquid films. Byclassifying the background materials by their optical properties, a reduced set of spectra was created as referencesignatures for automatic identification. Based on the radiative transfer model, an automatic identification algorithm wasimplemented. Measurements were performed with an imaging Fourier transform spectrometer developed at TUHH. Theresults of the analysis are displayed by a video image overlaid with an image of the identified liquid. Various liquids ondiverse surfaces were identified automatically. In addition to active measurements, passive measurements without anartificial source of radiation were performed. The results presented show that by means of the radiative transfer model,automatic remote identification of liquid contamination is possible.