The Sky Polarization Observatory (SPOrt): a project to measure the diffused sky polarization from the International Space Station Alpha (ISSA)

Abstract The Sky Polarization Observatory (SPOrt), a project to measure the diffused sky polarization in the frequency range of 22–90 GHz from the International Space Station, is described in its current configuration. Some preliminary considerations about the general topic of polarization in radiometric observations are made, in order to introduce the importance of polarimetric measurements in the more general context of Cosmic Microwave Background observations. The International Space Station is also introduced as a quite good opportunity to address such problematics.