HR: 09:45h
AN: A11D-06    [Abstracts]
TI: Looking Beyond the Lamppost: Finding Keys to Discovery in Off-Nadir and Multiangle Remote Sensing
AU: * Diner, D J
EM: djd@jord.jpl.nasa.gov
AF: Jet Propulsion Laboratory, Caltech, MS 169-237, 4800 Oak Grove Drive, Pasadena, CA 91109 United States
AU: Davies, R
EM: roger@jord.jpl.nasa.gov
AF: Jet Propulsion Laboratory, Caltech, MS 169-237, 4800 Oak Grove Drive, Pasadena, CA 91109 United States
AU: Kahn, R A
EM: kahn@jord.jpl.nasa.gov
AF: Jet Propulsion Laboratory, Caltech, MS 169-237, 4800 Oak Grove Drive, Pasadena, CA 91109 United States
AU: Martonchik, J V
EM: jvm@jord.jpl.nasa.gov
AF: Jet Propulsion Laboratory, Caltech, MS 169-237, 4800 Oak Grove Drive, Pasadena, CA 91109 United States
AU: Garay, M J
EM: garay@jord.jpl.nasa.gov
AF: Jet Propulsion Laboratory, Caltech, MS 169-237, 4800 Oak Grove Drive, Pasadena, CA 91109 United States
AU: Di Girolamo, L
EM: larry@atmos.uiuc.edu
AF: University of Illinois at Urbana-Champaign, 105 S. Gregory St., Urbana, IL 61801 United States
AB: For many years, single-angle observations of clouds and aerosols have been the mainstays of satellite remote sensing, with "off-nadir effects" typically considered sources of bias or error. Yet as with the individual who searches under a lamppost for lost keys because the light is better, this familiar view does not factor in the benefits of casting the observational net more broadly. For many applications, the intrinsic power of multispectral observations is magnified when expanded to a multiangle perspective. Further, data from sensors having routine global coverage and ever-improving resolution (e.g., POLDER, ATSR, MISR) have demonstrated the ability to turn panoramic, multiangle vision from a source of confusion to a wellspring of structural and morphological information that cannot be gleaned from, or requires fewer underlying assumptions than, single-angle approaches. We identify new pathways to atmospheric discovery using illustrations from the 9-angle MISR experiment on Terra. Retrievable quantities with benefits to climate, weather, and environmental studies include aerosol properties over challenging surfaces (including bright deserts and Case 2 waters) using bidirectional reflectance to decouple surface and atmospheric effects; aerosol microphysical properties such as particle shape by sampling the scattering phase function; cloud-top heights derived geometrically, independent of radiometric calibration, temperature profiles, or cloud emissivities; cloud-track wind estimates from feature identification across multiple views; 3-D cloud morphologies constructed by looking down cloud sides; and distinctions between polar clouds and surface ice based on their angular scattering. Directional radiation measurements also provide independent checks on model assumptions conventionally used in satellite retrievals, such as the use of 1-D radiative transfer (RT) theory, and demonstrate the importance of developing more sophisticated, 3-D approaches. We will incorporate examples of capabilities that were unanticipated or conceptual before launch, and discuss the importance of multiangular perspectives in characterizing environments containing both aerosols and clouds. A discussion of future multiangle sensor evolution, and the importance of advances in RT modeling, will be included.
UR: http://www-misr.jpl.nasa.gov
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0321 Cloud/radiation interaction
DE: 1794 Instruments and techniques
DE: 3311 Clouds and aerosols
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005