First spectral measurement of the Earth's upwelling emission using an uncooled wideband Fourier transform spectrometer

Abstract The first spectral measurement of Earth’s emitted radiation to space in the widebandrange from 100 to 1400cm −1 with 0.5cm −1 spectral resolution is presented. The mea-surement was performed from a stratospheric balloon in tropical region using a Fourier 5 transform spectrometer, during a field campaign held in Brazilin June2005. The instru-ment, which has uncooled components including the detector module, is a prototypedeveloped as part of the study for the REFIR (Radiation Explorer in the Far InfraRed)space mission. This paper shows the results of the field campaign with particular atten-tion to the measurement capabilities of the prototype. The results are compared with 10 measurements taken by IASI-balloon (Infrared Atmospheric Sounding Interferometer –Balloon version), aboard the same platform, and with forward model estimations. Theinfrared signature of clouds is observed in the measurements. 1 Introduction The observation of the upwelling emission in the full relevant spectral range, from the