SMOS soil moisture validation: status at the Upper
Danube cal/val site eight months after launch

SMOS cal/val proposal: AO ID 3236


Johanna Dall‘Amico1, Alexander Löw2, Florian Schlenz1, Wolfram Mauser1
1University   of Munich, Department of Geography, Munich, Germany
2Max-Planck-Institute   for Meteorology, KlimaCampus, Hamburg, Germany




 Funded by German Aerospace
 Center (50EE0731)
    Cal/val approach
    The Upper Danube Catchment cal/val site
    Overview campaigns and data
    Preliminary SMOS data analysis
    Conclusions and outlook




IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
Objectives


SMOS cal/val objectives

 Validate SMOS products
      Soil moisture (L2)
      Brightness temperatures (L1c)

 ... over
      a large area (entire Upper Danube)
      a smaller, but well instrumented area (Vils)

 ... using
      Field measurements
      Large scale land surface modelling
      Ancillary remote sensing data


IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
Approach




                              2   1km
  1
                 validation




                                   Land surface              Soil moisture          SMOS
Soil moisture station              Model (PROMET)                                   L2 SM product
   IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
Approach



                                                                      „L1c Brightness
                                                                      temperature“           SMOS
  3                                  L-MEB

                   validation             Radiative                    comparison
                                          Transfer
                                           model

                                                                              L2
                                                                              Processor
      Radiometer
                                2   1km
  1
                   validation


                                                                             API
                                     Land surface            Soil moisture          SMOS
Soil moisture station                model PROMET                                   L2 SM product
   IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
Approach

                   • Two airborne campaigns
                   •Comparison with ancillary remote sensing
                   data: soil moisture product from ENVISAT
                                                                       „L1c Brightness
                   ASAR (VISTA GmbH)                                                         SMOS
                                                                       temperature“
  3                                  L-MEB

                   validation             Radiative                     comparison
                                          Transfer
                                           model

                                                                                L2
                                                                                Processor
      Radiometer
                                2   1km
  1
                   validation


                                                                               API
                                     Land surface              Soil moisture         SMOS
Soil moisture station                model PROMET                                    L2 SM product
   IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
Upper Danube Catchment                                            Vils test site




                                                      Radiometer




Size: 77000 km²



IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
Instrumentation Vils test site

Soil moisture
     •   Profile (5 probes per station:
         2x5,10,25,40cm )
           – TDR Probes (IMKO
               GmbH)
           – ECHO probes
               (Decagon)
     •   Automatic data transmission
     •   Start: 2007 (one station since
         2002)


Meteorological data
     •   Precipitation
     •   Longwave radiation
     •   Temperature (2m)
     •   Wind speed
     •   Solar radiation
                                                               50 km
     •   Relative humidity
     •   Temperature @ 5,40 cm
1

IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
Land surface modelling

2




Meteorological data from a           PROMET land surface model
dense network of in situ stations
(NRT availability; subset shown)



 IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
Model validation

PROMET model has been extensively validated and is still
  being validated regularly using in-situ data




IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
ELBARA 2 radiometer

                                                                                          3




Meteorological
data                    Rape             Grassland




IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
ELBARA 2 radiometer


Data of ELBARA available through a web client
(full access to instrument ancillary data)




IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
SMOS airborne campaigns
   Rehearsal campaign 2008
SMOS validation campaign 2010
SMOS cal/val campaigns




                                                           EMIRAD
                                                           (Technical University of Denmark)


Thermal camera
(Max-Planck-Institute
for Meteorology, Hamburg)




                            HUT-2D radiometer
                            (Aalto University, Helsinki)
Radiometer data comparison 2008


                                                     EMIRAD minus HUT-2D after temperature correction
                                            30
                                            20
                                            10                                                          Lochheim
                        first stokes parameter [K]
                                             0                                                          Engersdorf
                                           -10                                                          South
                                                                                                        Engersdorf
                                           -20                                                          North
                                                                                                        Steinbeissen
                                           -30                                                          South
                                           -40                                                          Steinbeissen
                                                                                                        North
                                           -50
                                           -60
                                             08/04/2008                          15/04/2008
                                                           flight days during rehearsal campaign 2008


Two complementary radiometers during SMOS airborne campaigns
  provide added value:
- HUT-2D: imaging system, good spatial resolution
- EMIRAD: better radiometric calibration

IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
SMOS cal/val campaign 2010


   Five flights: 17, 22, 25 May,
    12, 17 June 2010

   Most overflights covered 10
    ground stations and the
    ELBARA radiometer (white)
    and 5 focus areas (red)

   Intensified ground campaign
    compared to 2008

   Basic objective
      •   Representative coverage of
          parts of one SMOS pixel




    IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
SMOS cal/val campaign 2010


First data SMOS campaign 2010




      EMIRAD data on lake Chiemsee                    HUT-2D data example (black areas: forest)

IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
SMOS cal/val campaign 2010




                                                                 Vils test site




TIR brightness temperatures (raw data)




 IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
Field measurements 2010

Soil moisture
   60 points covering whole focus area (spacing ~ 500m)
   90 points covering smaller sub-area (spacing ~ 100 m)
   =>~ 3000 SM measurements per day in the whole Vils

Soil temperature

Vegetation parameters
   Height, phenology, biomass

Land cover mapping




IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
Conditions during campaign

   Different soil moisture conditions between saturated and medium dry
   Vegetation growth phase  optical depth
   Air temperature between
    10 and 30°C                                    Meteo data Neusling (014)

                                                          30
                                                                                                          Flights                                                                                                                                                                                                                                                                                                                       10
                                                                                                                                                                                                                                                                                                                                                                                                                                        9
                                                          25
                                                                                                                                                                                                                                                                                                                                                                                                                                        8




                                                                                                                                                                                                                                                                                                                                                                                                                                             precipitation [mm]
                                       temperature [°C]   20
                                                                                                                                                                                                                                                                                                                                                                                                                                        7
                                                                                                                                                                                                                                                                                                                                                                                                                                        6
                                                                                                                                                                                                                                                                                                                                                                                                                                                                  precipitation
                                                          15                                                                                                                                                                                                                                                                                                                                                                            5
                                                                                                                                                                                                                                                                                                                                                                                                                                                                  air temperature
                                                                                                                                                                                                                                                                                                                                                                                                                                        4
                                                          10
                                                                                                                                                                                                                                                                                                                                                                                                                                        3
                                                                                                                                                                                                                                                                                                                                                                                                                                        2
                                                          5
                                                                                                                                                                                                                                                                                                                                                                                                                                        1
                                                          0                                                                                                                                                                                                                                                                                                                                                                             0
                                                               15.05.2010 00:00
                                                                                  16.05.2010 05:00
                                                                                                     17.05.2010 10:00
                                                                                                                        18.05.2010 17:00
                                                                                                                                           19.05.2010 22:00
                                                                                                                                                              21.05.2010 03:00
                                                                                                                                                                                 22.05.2010 08:00
                                                                                                                                                                                                    23.05.2010 13:00
                                                                                                                                                                                                                       24.05.2010 18:00
                                                                                                                                                                                                                                          25.05.2010 23:00
                                                                                                                                                                                                                                                             27.05.2010 04:00
                                                                                                                                                                                                                                                                                28.05.2010 09:00
                                                                                                                                                                                                                                                                                                   29.05.2010 14:00
                                                                                                                                                                                                                                                                                                                      30.05.2010 19:00
                                                                                                                                                                                                                                                                                                                                         01.06.2010 00:00
                                                                                                                                                                                                                                                                                                                                                            02.06.2010 05:00
                                                                                                                                                                                                                                                                                                                                                                               03.06.2010 10:00
                                                                                                                                                                                                                                                                                                                                                                                                  04.06.2010 15:00
                                                                                                                                                                                                                                                                                                                                                                                                                     05.06.2010 20:00
IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
Dynamics of ground measurements

                                soil moisture ground measurements (coarse resolution grid)

                        45
                        40
soil moisture vol. %]




                        35
                                                                                                                        Lochheim
                        30                                                                                              Engersdorf
                        25                                                                                              Steinbeissen

                        20                                                                                              Neusling
                                                                                                                        Frieding
                        15
                        10
                               17.05.   22.05.   25.05.    28.05.   12.06.   14.06.                       17.06.   soil moisture ground measurements (high resolution grid)
                                                            time
                                                                                                         45
                                                                                                         40
                                                                                  soil moisture vol. %




                                                                                                         35                                                                     Engersdorf
                                                                                                         30                                                                     Steinbeissen
                                                                                                         25                                                                     Neusling

                                                                                                         20                                                                     Frieding

                                                                                                         15
                                                                                                         10
                                                                                                              17.05.    22.05.     25.05.   28.05.   12.06.   14.06.   17.06.
                                                                                                                                             date


                             IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
Stations vs. spatial mean




          SM station




                       Ground station measurements
                       (lines) and mean values of all
                       measurements at red points (dots
                       with standard deviation bars)




IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
Brightness temperatures


L-MEB

  Radiative
  transfer
   model
                                                                  290

                               Brightness temperature (TBh) [K]
                                                                  280
                                                                  270
                                                                  260
                                                                  250
                                                                                                           EMIRAD
                                                                  240
                                                                                                           PROMET+LMEB
                                                                  230
                                                                  220
  PROMET                                                          210
  soil moisture                                                   200
                                                                    17.5.10   27.5.10   6.6.10   16.6.10


                                           Mean values and standard deviations of all values
                                           falling into the central ISEA grid point in the Vils area



 IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
SMOS comparison
SMOS data UDC (Vils testsite)




Morning overpasses
SMOS data UDC (Vils testsite)
L1c comparison


Comparison of SMOS L1c Brightness temperatures with
  simulated brightness temperatures (coupled
  PROMET+LMEB)

Actual SMOS L1c data processing:                               L-MEB

• TB Filtering (Flags and additional)                             Radiative
                                                                  Transfer
• Combining polarized observations                                 model

• Rotation (Faraday and Geometric)
• Analysis per incidence angle


                                                                           PROMET
                                                                           soil moisture
IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
SMOS L1c vs. PROMET-LMEB

                                                                     Only morning overpasses (40°)

                Brightness temperature (TBh) [K]




                                                     17 April 2010                                   17 June 2010




IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
Project status

                                                          „L1c Brightness
                                                          temperature“          SMOS




                                                                              
                                  L-MEB

                 validation           Radiative            comparison


                                          
                                      Transfer



         
                                       model

                                                                   L2
                                                                   Processor
   Radiometer
                                1km
                 validation



                                                                               
         



          
Soil moisture station
                                          
                                  Surface state        
                                                  Soil moisture
                                                                  API

                                                                        SMOS
                                                                        L2 SM product
Conclusions and outlook


 UDC cal/val activities on their way

 More detailed analysis of campaign data in the next months

 More SMOS data analysis as soon as reprocessed L1c data
  and L2 data available




IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
Thanks!




Funded by German Aerospace
Center (50EE0731)

FR1.L10.5: SMOS SOIL MOISTURE VALIDATION: STATUS AT THE UPPER DANUBE CAL/VAL SITE EIGHT MONTHS AFTER LAUNCH

  • 1.
    SMOS soil moisturevalidation: status at the Upper Danube cal/val site eight months after launch SMOS cal/val proposal: AO ID 3236 Johanna Dall‘Amico1, Alexander Löw2, Florian Schlenz1, Wolfram Mauser1 1University of Munich, Department of Geography, Munich, Germany 2Max-Planck-Institute for Meteorology, KlimaCampus, Hamburg, Germany Funded by German Aerospace Center (50EE0731)
  • 2.
    Cal/val approach  The Upper Danube Catchment cal/val site  Overview campaigns and data  Preliminary SMOS data analysis  Conclusions and outlook IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
  • 3.
    Objectives SMOS cal/val objectives Validate SMOS products  Soil moisture (L2)  Brightness temperatures (L1c)  ... over  a large area (entire Upper Danube)  a smaller, but well instrumented area (Vils)  ... using  Field measurements  Large scale land surface modelling  Ancillary remote sensing data IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
  • 4.
    Approach 2 1km 1 validation Land surface Soil moisture SMOS Soil moisture station Model (PROMET) L2 SM product IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
  • 5.
    Approach „L1c Brightness temperature“ SMOS 3 L-MEB validation Radiative comparison Transfer model L2 Processor Radiometer 2 1km 1 validation API Land surface Soil moisture SMOS Soil moisture station model PROMET L2 SM product IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
  • 6.
    Approach • Two airborne campaigns •Comparison with ancillary remote sensing data: soil moisture product from ENVISAT „L1c Brightness ASAR (VISTA GmbH) SMOS temperature“ 3 L-MEB validation Radiative comparison Transfer model L2 Processor Radiometer 2 1km 1 validation API Land surface Soil moisture SMOS Soil moisture station model PROMET L2 SM product IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
  • 7.
    Upper Danube Catchment Vils test site Radiometer Size: 77000 km² IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
  • 8.
    Instrumentation Vils testsite Soil moisture • Profile (5 probes per station: 2x5,10,25,40cm ) – TDR Probes (IMKO GmbH) – ECHO probes (Decagon) • Automatic data transmission • Start: 2007 (one station since 2002) Meteorological data • Precipitation • Longwave radiation • Temperature (2m) • Wind speed • Solar radiation 50 km • Relative humidity • Temperature @ 5,40 cm 1 IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
  • 9.
    Land surface modelling 2 Meteorologicaldata from a PROMET land surface model dense network of in situ stations (NRT availability; subset shown) IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
  • 10.
    Model validation PROMET modelhas been extensively validated and is still being validated regularly using in-situ data IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
  • 11.
    ELBARA 2 radiometer 3 Meteorological data Rape Grassland IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
  • 12.
    ELBARA 2 radiometer Dataof ELBARA available through a web client (full access to instrument ancillary data) IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
  • 13.
    SMOS airborne campaigns Rehearsal campaign 2008 SMOS validation campaign 2010
  • 14.
    SMOS cal/val campaigns EMIRAD (Technical University of Denmark) Thermal camera (Max-Planck-Institute for Meteorology, Hamburg) HUT-2D radiometer (Aalto University, Helsinki)
  • 15.
    Radiometer data comparison2008 EMIRAD minus HUT-2D after temperature correction 30 20 10 Lochheim first stokes parameter [K] 0 Engersdorf -10 South Engersdorf -20 North Steinbeissen -30 South -40 Steinbeissen North -50 -60 08/04/2008 15/04/2008 flight days during rehearsal campaign 2008 Two complementary radiometers during SMOS airborne campaigns provide added value: - HUT-2D: imaging system, good spatial resolution - EMIRAD: better radiometric calibration IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
  • 16.
    SMOS cal/val campaign2010  Five flights: 17, 22, 25 May, 12, 17 June 2010  Most overflights covered 10 ground stations and the ELBARA radiometer (white) and 5 focus areas (red)  Intensified ground campaign compared to 2008  Basic objective • Representative coverage of parts of one SMOS pixel IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
  • 17.
    SMOS cal/val campaign2010 First data SMOS campaign 2010 EMIRAD data on lake Chiemsee HUT-2D data example (black areas: forest) IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
  • 18.
    SMOS cal/val campaign2010 Vils test site TIR brightness temperatures (raw data) IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
  • 19.
    Field measurements 2010 Soilmoisture  60 points covering whole focus area (spacing ~ 500m)  90 points covering smaller sub-area (spacing ~ 100 m)  =>~ 3000 SM measurements per day in the whole Vils Soil temperature Vegetation parameters  Height, phenology, biomass Land cover mapping IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
  • 20.
    Conditions during campaign  Different soil moisture conditions between saturated and medium dry  Vegetation growth phase  optical depth  Air temperature between 10 and 30°C Meteo data Neusling (014) 30 Flights 10 9 25 8 precipitation [mm] temperature [°C] 20 7 6 precipitation 15 5 air temperature 4 10 3 2 5 1 0 0 15.05.2010 00:00 16.05.2010 05:00 17.05.2010 10:00 18.05.2010 17:00 19.05.2010 22:00 21.05.2010 03:00 22.05.2010 08:00 23.05.2010 13:00 24.05.2010 18:00 25.05.2010 23:00 27.05.2010 04:00 28.05.2010 09:00 29.05.2010 14:00 30.05.2010 19:00 01.06.2010 00:00 02.06.2010 05:00 03.06.2010 10:00 04.06.2010 15:00 05.06.2010 20:00 IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
  • 21.
    Dynamics of groundmeasurements soil moisture ground measurements (coarse resolution grid) 45 40 soil moisture vol. %] 35 Lochheim 30 Engersdorf 25 Steinbeissen 20 Neusling Frieding 15 10 17.05. 22.05. 25.05. 28.05. 12.06. 14.06. 17.06. soil moisture ground measurements (high resolution grid) time 45 40 soil moisture vol. % 35 Engersdorf 30 Steinbeissen 25 Neusling 20 Frieding 15 10 17.05. 22.05. 25.05. 28.05. 12.06. 14.06. 17.06. date IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
  • 22.
    Stations vs. spatialmean SM station Ground station measurements (lines) and mean values of all measurements at red points (dots with standard deviation bars) IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
  • 23.
    Brightness temperatures L-MEB Radiative transfer model 290 Brightness temperature (TBh) [K] 280 270 260 250 EMIRAD 240 PROMET+LMEB 230 220 PROMET 210 soil moisture 200 17.5.10 27.5.10 6.6.10 16.6.10 Mean values and standard deviations of all values falling into the central ISEA grid point in the Vils area IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
  • 24.
  • 25.
    SMOS data UDC(Vils testsite) Morning overpasses
  • 26.
    SMOS data UDC(Vils testsite)
  • 27.
    L1c comparison Comparison ofSMOS L1c Brightness temperatures with simulated brightness temperatures (coupled PROMET+LMEB) Actual SMOS L1c data processing: L-MEB • TB Filtering (Flags and additional) Radiative Transfer • Combining polarized observations model • Rotation (Faraday and Geometric) • Analysis per incidence angle PROMET soil moisture IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
  • 28.
    SMOS L1c vs.PROMET-LMEB Only morning overpasses (40°) Brightness temperature (TBh) [K] 17 April 2010 17 June 2010 IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
  • 29.
    Project status „L1c Brightness temperature“ SMOS   L-MEB validation Radiative comparison  Transfer  model L2 Processor Radiometer 1km validation    Soil moisture station  Surface state  Soil moisture API SMOS L2 SM product
  • 30.
    Conclusions and outlook UDC cal/val activities on their way  More detailed analysis of campaign data in the next months  More SMOS data analysis as soon as reprocessed L1c data and L2 data available IEEE International Symposium on Geoscience and Remote Sensing - IGARSS 2010 in Honolulu
  • 31.
    Thanks! Funded by GermanAerospace Center (50EE0731)