Development of a spectral-spatial calibration source for a Far-Infrared interferometer

The development of a spectral-spatial calibration source suitable for a double Fourier modulating interferometer at infrared wavelengths, or more generally a thermal IR or spectral imager, is described. In particular a calibrator is being developed by alternating, on the emitting surface, materials of different emissivities. Its characterization and the rationale behind this choice is given, together with some preliminary validation tests. Finally a discussion on the performances and future improvements is provided.