Calibration of a bispectral infrared push-broom imager

Kurzfassung

In May 2001 was planned to launch the small satellite BIRD, but the launch was shifted to August/September 2001. The main payload is dedicated to the observation of high temperature events and consists mainly of a Bi-Spectral IR Push Broom Scanner and a Push Broom Imager in the Visible. Solid state detector arrays with adaptive high dynamic front end electronics and advanced digital signal processing capabilities are the key element of IR imaging devices. With respect to the main mission objectives besides the high radiometric requirements to the detectors their mutual geometrical alignment is essential. The main problem of the radiometric calibration is the required high dynamic range which makes necessary to consider the non linear characteristic of the detector elements. On the other hand the application of special bi-spectral methods requests a carefully geometrical calibration. Besides the alignment of the different spectral channels the knowledge of the PSF is necessary. The laboratory radiometric and geometrical calibration procedures are described in this paper.