Cal/Val SMOS

Calibration and validation of SMOS brightness temperature

Cal/Val SMOS

The project Calibration and Validation of SMOS brightness temperature over the Salar de Uyuni (ESA SMOS Cal/Val Announcement of Opportunities ID 6317) aimed at calibrating the SMOS radiometer instrument.

The calibration of the instrument must be carried out measuring ground targets of known brightness temperature. Such targets are required to be radiometrically homogeneous in space over areas many times larger than the SMOS footprint and also over time.

The Salar de Uyuni is the largest salt flat in the world. It is located in the Bolivian Altiplano at a height of about 3700 m. The Salar de Uyuni is a large, flat and radiometrically homogeneous area. Its extent is several tenths the SMOS footprint and its emissivity is high and rather homogeneous except when flooded (about 3 months per year). It is located in a rather uninhabited area where no RFI is to be expected, providing a perfect SMOS calibration hot point.

The SMOS satellite was launched in November 2009, and first data was available two months later for the teams involved in calibration and validation of these data. Before the SMOS launch, the radiometric temporal and spatial signature of the Salar was characterized using data from the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) on-board Aqua. The study confirmed the Salar as a perfect radiometric calibration target.

isardSAT main duty was to monitor the temporal evolution and compare it to other satellite data.


M.J. Escorihuela1, P. Richaume and Y. H. Kerr ″SMOS calibration and validation over the Salar de Uyuni″ ESA Living Planet Symposium 9 - 13 September, 2013 Edinburgh, United Kingdom, 2013

M.J. Escorihuela, A. Escorihuela, P. Richaume and Y. Kerr ‘SMOS calibration and validation over the Salar de Uyuni’ IEEE Geoscience and Remote Sensing Symposium 22 - 27 July 2012, Munich, 2012

A. Escorihuela, M.J. Escorihuela, Y.H. Kerr, P. Richaume and J.P. Wigneron ″SMOS and AMSR-E brightness temperature cross-validation over the Salar de Uyuni″ SMOS Science Workshop 27-29 September 2011 Arles, France, 2011

M.J. Escorihuela, Y. Kerr, P. Richaume, J.P. Wigneron, and M. Roca, “Calibration and Validation of SMOS Brightness Temperature over the Salar de Uyuni.,” ESA Living Planet Symposiun 28 June-2 July 2010, Bergen, Norway, 2010

M.J. Escorihuela, Y. Kerr, P. Richaume, J.P. Wigneron and M. Roca ”SMOS brightness temperature validation over the Salar de Uyuni” SMOS Validation and Retrieval Team (SVRT) Workshop, 11-13 March 2009, Lisbon, Portugal, 2009






satellites, instrumental calibration, geophysical validation, remote sensing, radiometry