ESTAR to SMOS Development of interferometric radiometry for remote sensing from space

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ESTAR to SMOS Development of interferometric
radiometry for remote sensing from space

• David M. Le Vine
• Goddard Space Flight Center
• Greenbelt, MD 20771

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Outline

• ESTAR
• Short History
• Description
• Plans for Space
• Hydrostar
• SMOS
• Today 2D-STAR
• Lessons Learned
• RFI
• Scene Dependent Calibration
• Null feed back

ESTAR image of Delmarva Peninsula south of
NASAs Wallops Island Facility
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ESTAR

• Hybrid
• Real along track
• Synthetic across track
• Antenna Array
• 8-element dipole stick
• H-pol only
• 5 sticks
• 7 baselines
• Objective
• Demonstrate viability of aperture synthesis for
  remote sensing
• Apply to SM and OS

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ESTAR Hardware
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Walnut Gulch Watershed
ESTAR Image
TB vs Soil Moisture
ESTAR (Solid) PBMR (open)
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Remote Sensing Campaigns

• Soil Moisture
• Walnut Gulch Watershed 1991
• Little Washita Watershed 1992, 1994
• Southern Great Plains Experiment SGP- 97,-99
• Soil Moisture Experiment SMEX-02
• Ocean Salinity
• Delaware Coastal Current Experiment, 1993
• Gulf Stream Experiment, 1999

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HYDROSTARESTAR in Space Proposed to First NASA
ESSP Call
Deployed Resolution lt 30 km ( 5.8 x 9.5 m
array)
Deployment of Antenna (16 Slotted Waveguide
Sticks)
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2D-STAR

• Synthesis in two dimensions
• Array of patch antennas
• Multiple configurations
• V and H-pol

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2D-STAR Installed on NASA P3-B Aircraft
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SMEX-03 Huntsville, AL
Above Landsat, false color image of SMEX-03
site. Tennessee River at lower right. Right
2D-STAR image during SMEX-03 H-pol (top) and
V-pol (bottom)
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Lessons Learned
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RFI is a problem even in the restricted band at
1.413 GHz
ESTAR image crossing the Chesapeake Bay near
Richmond, Virginia showing effects of RFI
RFI in zero spacing channel
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Noise Injection is Stable

• Used for ESTAR zero spacing
• Employed Basic Correlator
• Proved to be extremely stable

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ESTAR to SMOS Development of interferometric
radiometry for remote sensing from space

• David M. Le Vine
• Goddard Space Flight Center
• Greenbelt, MD 20771

C. Swift, T. Jackson, A. Tanner, C. Ruf, A.
Griffis, J. Isham, P. Gaiser, M. Goodberlet , M.
Haken, J. Fuchs, R. Aldridge, ProSensing Staff,
M. Kao, J. Good
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BACK UP
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Scene Dependent Artifacts

• Reconstruction noise
• G-matrix (anechoic chamber)
• Antenna coupling
• Scene dependence
• Gibbs phenomena
• ESTAR
• Coupled with incidence angle
• Scene-dependent Inverse filter