A wide-band nadir-sounding spectroradiometer for the characterization of the Earth's outgoing longwave radiation

A balloon-borne wide-band Fourier transform spectrometer named REFIR-PAD (Radiation Explorer in the Far InfraRed, Prototype for Applications and Development) has been developed at CNR-IFAC to perform the characterisation of the Earth's outgoing long-wave radiation in the far-infrared region. The spectroscopic characterisation of this region is expected to increase greatly our level of knowledge of the radiative effects of water content in the upper troposphere. The REFIR-PAD instrument provides spectrally-resolved nadir-sounding radiance measurements in the 100-1400 cm-1 range, with a 0.5 cm-1 resolution, covering the most part of the Earth's long-wave emission and including both the far-infrared and the better known middle-infrared region. REFIR-PAD was flown as a piggy-back payload on the CNES IASI-LPMAA stratospheric balloon gondola in June 2005 from Teresina, Brazil. The data collected in this mission, will provide valuable information for the development of a future space mission aimed to the operational monitoring of the upper troposphere water vapour and clouds in order to identify their climate signatures.