Optics: measuring and testing – By dispersed light spectroscopy
Patent
1999-06-25
2000-08-29
Evans, F. L.
Optics: measuring and testing
By dispersed light spectroscopy
356326, 3562431, G01J 300, G01N 2193
Patent
active
061116408
ABSTRACT:
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.
REFERENCES:
Sandor-Leahy, Digital Avionics Systems Conference, 1998. Proceedings., 17th DASC. The AIAA/IEEE/SAE, vol.: 2, 1998, pp. H44/1-H44/8 vol. 2 The conference was held Oct. 31-Nov. 7, 1998.
Albert Tebo, "Imaging spectrometers are at home in space, in aircraft, and on the ground--almost,"OE Reports, Jul. 1995.
Spectralon Wavelength Calibration Standards.
Stephanie Sandor-Leahy et al., "The TRWIS III hyperspectral imager: instrument performance and remote sensing applications", Proceedings of the SPIE, Jul. 1998, vol. 3438, pp. 13-22.
Hedman Theodore R.
Jarecke Peter J.
Liao Lushalan B.
Evans F. L.
TRW Inc.
Yatsko Michael S.
LandOfFree
Hyperspectral imaging spectrometer spectral calibration does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Hyperspectral imaging spectrometer spectral calibration, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hyperspectral imaging spectrometer spectral calibration will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1254733