The PRISMA hyperspectral imaging spectrometer: detectors and front-end electronics

Two detectors, SWIR and VNIR, and relevant front-end electronics were developed in the frame of the PRISMA(Precursore Iperspettrale della Missione Applicativa) project, an hyperspectral instrument for the earth observation. The two detectors were of the MCT type and, in particular, the VNIR was realized by Sofradir by using the CZT(Cadmium Zinc Telluride substrate of the PV diodes) substrate removal to obtain the sensitivity in the visible spectral range. The use of the same ROIC permitted to design an unique front-end electronics. Two test campaigns were carried out: by Sofradir, only on the detectors, and by Selex ES, by using the PRISMA flight electronics. This latter tests demonstrated that was possible to obtain the same detector performance, with respect of those ones obtained by a ground setup, with a flight hardware in terms of noise, linearity and thermal stability.