About the effects of instrument errors in interferometric radiometry

Abstract

[1] The SMOS mission is a European Space Agency (ESA) project aimed at global monitoring of surface soil moisture and sea surface salinity from radiometric L-band observations. The radiometer onboard SMOS uses a 2-D synthetic aperture concept in order to achieve satisfactory spatial resolution performances for a minimal cost in terms of payload mass and volume. As the satellite moves ahead, every area on Earth's surface is seen at a variety of incidence angles. This multiangular capability is used in the retrieval of geophysical parameters. A major issue for obtaining useful measurements of the surface salinity is the radiometric accuracy, since the overall dynamic range resulting from ocean salinity variations only extends over a few Kelvin. To improve instrument performances, it is foreseen that independent retrieved salinity estimates will be averaged over a suitable space/time domain. This should bring random uncertainties due to radiometric sensitivity down to around 0

Validation of Soil Moisture and Ocean Salinity (SMOS) Soil Moisture Over Watershed Networks in the U.S.

“…Therefore, some of the variation in tau we observed in Figure 16 4a may be related to brightness temperature variations associated with this issue. Additional details on aliasing can be found in [25][26][27][28].…”

Dissection multi-échelle de quelques systèmes naturels : de la cryosphère Antarctique aux pulsations solaires

“…Les sciences de l'univers sont principalement des sciences d'observation pour lesquelles le laboratoire est le milieu naturel lui-même, qu'il soit océan, atmosphère, ciel ou Terre. Si les méthodes d'observation jouent un rôle central dans l'étude des milieux naturels, c'est parce qu'elles s'assortissent de développements additionnels spécifiques, faisant appel au traitement du signal et des images, aux mathématiques appliquées età l'analyse numérique [1]. En outre, la question du traitement de l'information se pose bien souvent déjà au moment-même de la définition d'un instrument, de ses objectifs scientifiques, de ses performances attendues.…”

Preface to special section: Remote Sensing of the Earth's Environment by Microwave Radiometers and Radar

“…Other topics included calibration of frequency modulated continuous wave (FMCW) millimeter-wave radars, synthetic aperture radar (SAR), and polarimetric radars. The paper by Anterrieu et al [2003] describes the Soil Moisture and Ocean Salinity (SMOS) mission, which is a European Space Agency-led project aimed at global monitoring of surface soil moisture and sea surface salinity from spaceborne radiometric L-band observations. Capsoni and Caboni [2003] show that radiometers can be used to calibrate a single parameter radar and specifically to define the relationship between radar reflectivity and specific attenuation.…”