On June 30th, 2005 the REFIR-PAD (Radiation Explorer in the Far InfraRed-Prototype for Application and
Development) Fourier transform spectroradiometer performed the first wide-band spectral characterization of the
top-of-atmosphere emitted radiation in the far-infrared with an uncooled instrument. The nadir emitted radiance
has been measured down to 100 cm-1, thus covering a spectral interval that, until now, was nearly unexplored,
and up to 1400 cm-1, including the well characterized atmospheric window region, in which it is possible to
perform comparison and intercalibration with operative instruments. The measurements were performed at an
altitude of 34 km, from a stratospheric balloon launched in tropical region, near Teresina (Brazil). The acquired
spectra have a spectral resolution of 0.5 cm-1. It should be noted that despite the operating spectral range
extending to the far-infrared region, REFIR-PAD does not require any cooled components, thanks to the use of
pyroelectric detectors and an optical scheme that compensates for the instrument self-emission. This work shows
the results of the analysis of the spectra, focusing on the far infrared portion of the atmospheric emitted radiance.
The retrieval of the vertical profiles of water vapour and temperature during the flight is presented. The vertical
resolution of the retrieval is 2 km in the upper troposphere-lower stratosphere (UTLS) region, and lower at
higher altitudes. The comparison with ECMWF for validation is also shown. Besides the characterization of
temperature and water vapour, from the analysis of the emitted radiance useful information can be gathered
about cloud and aerosol contribution to radiation budget.