| 摘要 |
A method of calibrating a hyperspectral imaging spectrometer. A PTFE panel (26) having substantially 100% reflectance across a spectrum of interest is mechanically inserted into the spectrometer's field-of-view. The panel (26) is illuminated by a lamp (22, 24), such as a quartz Tungsten Halogen lamp, so that reflected radiation from the panel (26) floods the spectrometer's FOV. The image generated by the spectrometer is electronically stored. Next, the reflectance panel (26) is removed and replaced with a PTFE panel (40) that is doped with a rare earth element, such as holmium oxide, dysprosium oxide, erbium oxide or other dopants. The dopant serves the purpose of producing many distinct absorption features in the reflected spectra whose wavelengths spacings and absorption line widths are precisely known. The image obtained form the doped PTFE panel (40) is then electronically stored. The image obtained from the doped PTFE panel (40) is divided by the image obtained from the reflectance PTFE panel (26) on a pixel-by-pixel basis to obtain a measurement of the absorption spectra of the dopant. The measured spectra is compared to the known spectra as a function of spatial position across the focal plane of the spectrometer to obtain the spectral calibration. A center wavelength is then assigned to each pixel in the FPA based on the calibration.
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