Polarization SurfaceState Retrieval in the Presence of Atmospheric Perturbations

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Polarization Surface-State Retrieval in the
Presence of Atmospheric Perturbations

• Mentor Dr. Carol Bruegge (JPL)
• By Victor Chu

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Who

• Funding Non-NASA contract
• ICATS project (Image Chain Analysis Technology
  for Space)
• Orbiting Carbon Observatory (OCO)
• OCO requires knowledge of surface polarization
  properties for its retrieval algorithm
• The task utilizes a retrieval code also used by
  OCO
• Multiangle SpectroPolarimetric Imager (MSPI)
• JPL polarimeter built to study aerosols

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Pre-Cursor

• Multi-angle Imaging SpectroRadiometer (MISR)
• Orbit since 1999
• 275m resolution
• 0º, 26º, 46º, 60º, and 70º fore and aft of nadir
• Spectral Bands - 446, 558, 672, 866 nm
• Multi-angle Unique Capabilities

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What it can do
MISR generated image Enhanced sensitivity to
aerosols
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Polarization

• MISR lacks Polarization Sensor
• Polarization Adds New Dimension
• New level of clarity

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What it COULD do

• Camouflaged objects are difficult to detect with
  MISR
• Polarization makes objects appear extremely clear
  regardless

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Do you see any trucks?
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What about now?
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See them now?
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MSPI

• Follow-on instrument to MISR
• Many factors affect polarimetric accuracy
• Requires calibration

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Radiative Programs

• VLIDORT
• Few Polarization calculators
• MODTRAN
• Developed by the Air Force Geophysical Laboratory
  (AFGL)
• MODTRAN 5
• ICATS team has access to MODTRAN 4P beta

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Effects of Aeresol
Ground Downwelling Ground
Upwelling Satellite Upwelling
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Degree of Linear Polarization
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Effects of Gases
Ground Downwelling Ground
Upwelling Satellite Upwelling
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Degree of Linear Polarization
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Future Plans

• Simulations of test scenes
• Identify surfaces given Stokes parameters
• Measurement capability
• Validation of both VLIDORT and MODTRAN 4P

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Acknowledgements

• Dr. Carol Bruegge, Mentor
• Vijay Natraj, VLIDORT expert
• Rob Spurr, VLIDORT author
• SURF office for program organization

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References

• D. Diner, A. Davis, R. Chipman, Innovative
  Technology Approach for High-Accuracy Imaging
  Spectropolarimetry at Multiple View Angles,
  project proposal for funding, 2006.
• Spurr, Robert J.D. VLIDORT A linearized
  pseudo-spherical vector discrete ordinate
  radiative transfer model for forward model and
  retrieval studies in multilayer multiple
  scattering media. JQSRT 2006 in press.
• T. Takashima, K. Masuda, Degree of radiance and
  polarization of upwelling radiation from an
  atmosphere-ocean system, Applied Optics 24, 15,
  2423 (1985)
• T. Cronin, E. Warrant, B Greiner, Celestial
  polarization patterns during twilight, Applied
  Optics 45, 22, 5582 (2006)
• G.N. Plass, G.W. Kattawar, Polarization of the
  Radiation Reflected and Transmitted by the
  Earths Atmosphere, Applied Optics 9, 5, 1122
  (1970)
• J. S. Tyo, D. L. Goldstein, D. B. Chenault, J. A.
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  remote sensing applications, Applied Optics 45,
  22, 5453 (2006