Patent ID: 6819798
Filing Date: 2004-11-16
Classification: G01J

Abstract:
A method for detecting spectral drift in a hyperspectral imaging system, comprising the steps of:(a) obtaining in-field measurements of a response function for a calibration filter; (b) obtaining in-field measurements of a response function for an onboard blackbody; (c) determining a spectral transmittance function using said response functions from steps (a) and (b) for said calibration filter and said onboard blackbody; (d) determining a first derivative function of said spectral transmittance function; (e) separating said first derivative function into a plurality of spectral band regions, each of said spectral band regions having +/âˆ’ N pixels on either side of a localized minima; (f) determining a pixel shift magnitude value for one of said plurality of spectral band regions; and (g) applying said pixel shift magnitude value to a look-up table to determine a magnitude and direction of said spectral drift for one of said plurality of spectral band regions.