Data processing technique applied to the calibration of a high performance FPA infrared camera

The present work deals with the calibration of a focal plane array infrared camera whose detector is a matrix of 320 x 244 PtSi sensors active in the range 3.6-5 mum. The calibration curve has been obtained by measuring the energy emitted by a blackbody, consisting in a copper cylindric cavity with isothermal walls. The results, obtained in the temperature range 10-70 degreesC, enable us to investigate the nature of the noise which affects the measurements. The aim is to suggest a data processing and a calibration technique in order to enhance the image quality and the instrument response as well. The effects of random uncertainties have been reduced by using Wiener filtration, which enables us to improve the signal to noise ratio. The problem caused by the nonuniform response of the detector array has been handled by using a different calibration curve for each sensor. The effectiveness of this procedure has been checked by comparing the frequency histograms of the raw and the processed signal. The investigation enables us to highlight some peculiar features of the new focal plane array technology employed in the new generation infrared cameras. (C) 2002 Elsevier Science B.V. All rights reserved.