Use of AMSR-E Land Parameter Modeling and Retrievals for SMAP Algorithm Development Steven Chan Eni Njoku Joint AMSR Science Team Meeting Telluride, Colorado July 14-16, 2008 The SMAP Algorithm Development Testbed Purposes: An L-band mission simulator (simulated TBs to be as realistic as possible) Modules capable of testing multiple algorithms subject to the same inputs Features: Realistic orbital and instrument sampling Global and continental scales Annual cycle(s) Steven K. Chan Joint AMSR Science Team Meeting Telluride, Colorado Jul 14-16, 2008 An end-to-end Observing System Simulation Experiment (OSSE) for SMAP The SMAP Algorithm Development Testbed Anticipated Benefits: Investigate relative strengths/weaknesses of different retrieval algorithms Impacts of pursuing different science/instrument/mission trades Impacts of ancillary data uncertainties Steven K. Chan Joint AMSR Science Team Meeting Telluride, Colorado Jul 14-16, 2008 Realistic orbital and instrument sampling Major Testbed Components Excerpted from SMAP Algorithm Development Testbed for MCR in Jun 2008 Land surface model (LSM) input Forward microwave models (i.e. radiometer and radar) Steven K. Chan Joint AMSR Science Team Meeting Telluride, Colorado Jul 14-16, 2008 Environmental effects (e.g. Faraday rotation, galactic radiation) Instrument effects (e.g. instrument precision, calibration errors) Inverse models (e.g. radiometer, radar, and combined radar-radiometer) Error analysis Orbital and instrument sampling Testbed Flowchart Steven K. Chan Joint AMSR Science Team Meeting Telluride, Colorado Jul 14-16, 2008 LSM Input Parameters Surface Temp Soil Texture Vegetation Truth Soil Moisture Orbital/ Instrument Sampling Forward Models (radiometer/radar) Environmental Effects Instrument Effects TB, Inverse Models (radiometer/radar) Retrieved Soil Moisture Error Analysis Orbital and Instrument Sampling Steven K. Chan Joint AMSR Science Team Meeting Telluride, Colorado Jul 14-16, 2008 Altitude = 670km Sampling Period = 42ms Antenna = 6m Incidence = 40 SMAP Ground Tracks Orbital and Instrument Sampling (Radiometer) Steven K. Chan Joint AMSR Science Team Meeting Telluride, Colorado Jul 14-16, 2008 SMAP Instrument Sampling (boresight and antenna beam pattern) Major Testbed Components Excerpted from SMAP Algorithm Development Testbed for MCR in Jun 2008 Land surface model (LSM) input Forward microwave models (i.e. radiometer and radar) Steven K. Chan Joint AMSR Science Team Meeting Telluride, Colorado Jul 14-16, 2008 Environmental effects (e.g. Faraday rotation, galactic radiation) Instrument effects (e.g. instrument precision, calibration errors) Inverse models (e.g. radiometer, radar, and combined radar-radiometer) Error analysis Orbital and instrument sampling Land Surface Model Input Parameters Steven K. Chan Joint AMSR Science Team Meeting Telluride, Colorado Jul 14-16, 2008 Current scheme: Use geophysical data fields from GLDAS Soil Moisture Surface Temperature Sand Fraction Vegetation Water Content Soil Temperature Clay Fraction Advantages Steven K. Chan Joint AMSR Science Team Meeting Telluride, Colorado Jul 14-16, 2008 Antenna sampling not well addressed: cell size (above) >> SMAP footprint Simulated TBs may have QC issues due to unrealistic inputs Inputs may introduce unreal spatial and temporal correlations Convenience: one-stop portal of geophysical input data fields Fields are consistent with the underlying land model that generates them Potential Limitations Major Testbed Components Excerpted from SMAP Algorithm Development Testbed for MCR in Jun 2008 Land surface model (LSM) input Forward microwave models (i.e. radiometer and radar) Steven K. Chan Joint AMSR Science Team Meeting Telluride, Colorado Jul 14-16, 2008 Environmental effects (e.g. Faraday rotation, galactic radiation) Instrument effects (e.g. instrument precision, calibration errors) Inverse models (e.g. radiometer, radar, and combined radar-radiometer) Error analysis Orbital and instrument sampling First Step Towards More Realistic Inputs/Outputs Steven K. Chan Joint AMSR Science Team Meeting Telluride, Colorado Jul 14-16, 2008 Proposed scheme: Use AMSR-E data fields ( ) to first optimize forward model and then extend its frequency dependence to L-band frequency AMSR-E Soil Moisture Forward Model at 6.9 GHz Forward Model at 10.7 GHz Forward Model at 18.7 GHz Simulated TBs at 6.9 GHz Simulated TBs at 10.7 GHz Simulated TBs at 18.7 GHz AMSR-E TBs at 6.9 GHz AMSR-E TBs at 10.7 GHz AMSR-E TBs at 18.7 GHz Optimal Model Parameters at 6.9 GHz Optimal Model Parameters at 10.7 GHz Optimal Model Parameters at 18.7 GHz First Step Towards More Realistic Inputs/Outputs Steven K. Chan Joint AMSR Science Team Meeting Telluride, Colorado Jul 14-16, 2008 Frequency (GHz) Model Parameter (e.g. ) Use AMSR-E soil moisture and AMSR-E TBs to determine optimal model parameters at a given frequency Repeat the above procedure for other frequencies Explore frequency dependence of optimal model parameters and extend (extrapolate) their values to L-band frequency Radiative Transfer Forward Model Ts: surface temperature, rs: Fresnel reflectivities, : vegetation opacity : single-scattering albedo, h: surface roughness, Q: polarization mixing ratio Simulated L-band TB (1 Day) Steven K. Chan Joint AMSR Science Team Meeting Telluride, Colorado Jul 14-16, 2008 Simulated L-band TB (2 Days) Steven K. Chan Joint AMSR Science Team Meeting Telluride, Colorado Jul 14-16, 2008 Simulated L-band TB (3 Days) Steven K. Chan Joint AMSR Science Team Meeting Telluride, Colorado Jul 14-16, 2008 Summary Steven K. Chan Joint AMSR Science Team Meeting Telluride, Colorado Jul 14-16, 2008 SMAP Testbed as an end-to-end mission simulator Simulated L-band observations to be as realistic as possible AMSR-E data fields could be used to optimize forward model and extend its frequency dependence to L-band frequency, thus assisting the SMAP Testbed to generate realistic L-band observations