MIRAS Quality Control Reports

Quality Control Reports

SMOS Quality Control Reports are available in different varieties covering quality monitoring of science and calibration products, verification and validation of reprocessed products, providing monthly overviews of the health of MIRAS instrument, and any anomalies that may affect the quality of data acquired.

SMOS Monthly Quality Reports - Download SMOS data quality reports for operational (OPER) products.

SMOS Videos - Download SMOS Soil Moisture, SMOS Sea Surface Salinity, SMOS Brightness Temperature Land Surface, SMOS Brightness Temperature Sea Surface Weekly Maps.

Level 1 and Level 2 v7 reprocessed verification report - Download the report

Level 2 Soil Moisture v7  product validation report - Download the report

Level 2 Soil Moisture Neural Network v7 product  validation report - Download the report

MIRAS anomalies and mission impact - Download a technical note describing the anomalies that have occurred since MIRAS became operational, and may impact the quality of data acquired.

SMOS product availability - Find the details of the full history of SMOS product availability .

SMOS Mission Status - Download weekly reports on the availability of SMOS data and any anomalies that may have occurred.

 

MIRAS Calibration performances

Browse and download L1 long term calibration parameter plots, Brightness Temperature animated maps.

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Noise Injection Radiometers (NIRs) internal diode noise temperature (Tna) for vertical polarisation receiver (V) evolution since the beginning of the mission for the three NIR unit: AB (blue), BC (green) and CA (red). At the beginning of the mission Tna has evolved differently among the three NIR units until October 2014 when warm-NIR calibration was introduced. In this configuration the Sun is located slightly above the instrument horizon, improving NIR thermal stability and calibration accuracy noticeably. The unit CA has shown to be more stable, since beginning of the mission.

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Noise Injection Radiometers (NIRs) internal diode noise temperature (Tna) for horizontal polarisation receiver (H) evolution since the beginning of the mission for the three NIR unit: AB (blue), BC (green) and CA (red). At the beginning of the mission Tna has evolved differently among the three NIR units until October 2014 when warm-NIR calibration was introduced. In this configuration the Sun is located slightly above the instrument horizon, improving NIR thermal stability and calibration accuracy noticeably. The unit CA has shown to be more stable, since beginning of the mission.

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L-band Brightness Temperature evolution over Concordia Station (Dome-C Antarctica). SMOS measurements at 42 incidence angle averaged every 18 days at surface horizontal polarisation (blue line) and at surface vertical polarisation (green line).  In-situ DOMEX measurements at 42 incidence angle averaged over the same period at horizontal polarisation (red line) and at vertical polarisation (purple line). Reference value for July 2010 is subtracted.  SMOS brightness temperature evolution in vertical polarisation is very well correlated with in-situ measurements, stability, since the beginning of the mission, is within about 1K. The brightness temperature in horizontal polarisation is less stable and impacted by geophysical condition at surface level as confirmed by DOMEX measurement evolution. In particular,  the drift in horizontal polarisation  around beginning of 2015 was due to a change on surface geophysical condition due to snow accumulation since November 2014 and rapidly evolution of snow density on 22 March 2015 when a strong wind event has rapidly changed the surface condition and surface emissivity around Dome-C.    Differences in vertical and horizontal polarisation top of atmosphere absolute value between SMOS and DOMEX measurements are under investigation.

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Hovmoller plot for L-band brightness temperature differences between SMOS measurements and ocean forward model over Pacific Ocean (between 160 and 220 degree longitude) for ascending orbit direction and horizontal polarisation at antenna frame since June 2010. In-situ Analysis System (ISAS) Objective Analysis (OA) observatios were used in the ocean forward model to reduce the geophysical contribution in the differences. The straight blue line below the equator visible till December 2013 was due to Radio Frequency Interference (RFI) contamination around 180 deg longitude. Noise due to RFI is also present in years 2015 -2017 between latitude 0 deg. and 20 deg.

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Hovmoller plot for L-band brightness temperature differences between SMOS measurements and ocean forward model over Pacific Ocean (between 160 and 220 degree longitude) for descending orbit direction and horizontal polarisation at antenna frame since June 2010. In-situ Analysis System (ISAS) Objective Analysis (OA) observatios were used in the ocean forward model to reduce the geophysical contribution in the differences. Radio Frequency Interference (RFI) contamination is present in years 2016 -2017 between latitude 20 deg. and 40 deg.

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Hovmoller plot for L-band brightness temperature differences between SMOS measurements and ocean forward model over Pacific Ocean (between 160 and 220 degree longitude) for ascending orbit direction and vertical polarisation at antenna frame since June 2010. In-situ Analysis System (ISAS) Objective Analysis (OA) observatios were used in the ocean forward model to reduce the geophysical contribution in the differences. The straight blue line below the equator visible till December 2013 was due to Radio Frequency Interference (RFI) contamination around 180 deg longitude.

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Hovmoller plot for L-band brightness temperature differences between SMOS measurements and ocean forward model over Pacific Ocean (between 160 and 220 degree longitude) for descending orbit direction and vertical polarisation at antenna frame since June 2010. In-situ Analysis System (ISAS) Objective Analysis (OA) observatios were used in the ocean forward model to reduce the geophysical contribution in the differences.

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Evolution of the L-band brightness temperature differences between SMOS measurements and ocean forward model over Pacific Ocean (area between 160, 220 degree longitude and -60, +60 degree latitude) for horizontal and vertical polarisation at antenna frame since June 2010 for ascending orbit direction. In-situ Analysis System (ISAS) Objective Analysis (OA) observatios were used in the ocean forward model to reduce the geophysical contribution in the differences.

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Evolution of the L-band brightness temperature differences between SMOS measurements and ocean forward model over Pacific Ocean (area between 160, 220 degree longitude and -60, +60 degree latitude) for horizontal and vertical polarisation at antenna frame since June 2010 for descending orbit direction. In-situ Analysis System (ISAS) Objective Analysis (OA) observatios were used in the ocean forward model to reduce the geophysical contribution in the differences.

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Evolution of the L-band brightness temperature differences between SMOS measurements at descending and ascending orbit direction over Pacific Ocean (area between 160, 220 degree longitude and -50, +20 degree latitude) for first Stokes since June 2010.

 

References and further readings

  • IDEAS+ SMOS Team; Monthly quality report
  • M. Martín-Neira, R.Oliva, I. Corbella, F. Torres, N. Duffo, I. Duránc, J. Kainulainend, J. Closa, A. Zurita, F. Cabot, A. Khazaal, E. Anterrieu, J. Barbosa, G. Lopes, J. Tenerelli, R. Díez-García, J. Fauste, F. Martín-Porqueras, V. González-Gambau, A. Turiel, S. Delwart, R. Crapolicchio, M. Suess; SMOS instrument performance and calibration after six years in orbit; Remote Sensing of Environment 180 (2016) 19–39

Sea Surface Salinity

Browse and download L2 Sea Surface Salinity parameter plots, Sea Surface Salinity animated maps.

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Weekly maps of good quality sea surface salinity retrieved from SMOS measurements and corrected for land-sea contamination for ascending orbit direction are available in MP4 format. Lack of data in the maps is mainly due to contamination from Radio Frequency Interference (RFI) coming from land sites or ships and presence of sea-ice. In the descending file, Seasonal lack of good retrieval in the Northern Hemisphere is present during the period from November to February.

 

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Ocean Target Transformation (OTT) correction is computed daily by using about 10 previous orbits acquired over selected area and an ocean forward model. The OTT it is used to remove spatial biases in the brightness temperature images and it is needed to retrieve sea surface salinity. The plot shows the OTT latency time defined as the differences between the mean acquisition time of 10 orbits and the sensing time of the data acquisition processed with the OTT. Nominal latency time is about 6 days, periods with higher latency time indicates lack of data as in January 2011 due to on board execution of the instrument electrical stability test, or data rejection due to Radio Frequency Interference corrupted measurement as for example in April 2014.

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Evolution of the number of grid points with good quality sea surface salinity retrieved from SMOS measurements corrected for land-sea contamination and uncorrected since June 2010. Ascending orbit direction. Upper plot all grid points over ocean, bottom plot only for ocean grid points near the coast line (< 800 km).

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Evolution of the number of grid points with good quality sea surface salinity retrieved from SMOS measurements corrected for land-sea contamination and uncorrected since June 2010. Descending orbit direction. Upper plot all grid points over ocean, bottom plot only for ocean grid points near the coast line (< 800 km).

Soil Moisture Retrieval Performance

Browse and download L2 Soil Moisture parameter plots, Soil Moisture animated maps.

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Weekly maps of soil moisture retrieved from SMOS measurements for ascending and descending orbit directions are available in MP4 format. Lack of data in the maps is mainly due to contamination from Radio Frequency Interference (RFI) or specific surface condition like presence of snow, frozen soil, strong land topography.

 

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Evolution of number of successful retrieval of the surface dielectric constant per retrieval case for ascending orbit direction since June 2010. For cases: Soil and Forest cover soil moisture parameter is also successfully retrieved. For all others retrieval cases additional parameters like optical depth or surface roughness, surface temperature might be retrieved.

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Evolution of number of successful retrieval of the surface dielectric constant per retrieval case for descending orbit direction since June 2010. For cases: Soil and Forest cover soil moisture parameter is also successfully retrieved. For all others retrieval cases additional parameters like optical depth or surface roughness, surface temperature might be retrieved.

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Evolution of percentage of successful retrieval of the surface dielectric constant per retrieval case for ascending orbit direction since June 2010. For cases: Soil and Forest cover soil moisture parameter is also successfully retrieved. For all others retrieval cases additional parameters like optical depth or surface roughness, surface temperature might be retrieved.

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Evolution of percentage of successful retrieval of the surface dielectric constant per retrieval case for descending orbit direction since June 2010. For cases: Soil and Forest cover soil moisture parameter is also successfully retrieved. For all others retrieval cases additional parameters like optical depth or surface roughness, surface temperature might be retrieved.