Calibration of a Fourier transform spectrometer using three black body sources

A procedure to calibrate a Fourier transform spectrometer is presented. Blackbody sources of three different temperatures are used to eliminate errors in the calibration arising from the limited accuracy of the temperature measurement of the calibration sources. With three spectra of blackbodies it is possible to assume that the temperatures are unknown variables, as are the parameters of the functions describing the spectrometer. Nonlinear Gaussian balancing calculation is applied to determine these unknown variables and to minimize the influence of noise. A comparison between results obtained with this method and a conventional calibration procedure is presented.