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Polarimetric, Two-color, Photon-counting Laser Altimeter Measurements of Forest Canopy Structure and Composition
David
Harding, NASA GSFC, david.j.harding@nasa.gov
(Presenter)
The Slope Imaging Multi-polarization Photon-counting Lidar is a multi-beam, micropulse airborne laser altimeter that acquires active and passive polarimetric optical remote sensing measurements at visible and near-infrared wavelengths. SIMPL was developed to demonstrate advanced measurement approaches of potential benefit for improved, more efficient spaceflight laser altimeter missions. SIMPL data has been acquired for wide diversity of forest types in the summers of 2010 and 2011 in order to assess the potential of its novel capabilities for characterization of vegetation structure and composition. On each of its four beams SIMPL provides highly-resolved measurements of forest canopy structure by detecting single-photons with 15 cm ranging precision using a narrow-beam system operating at a laser repetition rate of 11 kHz. Associated with that ranging data SIMPL provides eight amplitude parameters per beam unlike the single amplitude provided by typical laser altimeters. Those eight parameters are received energy that is parallel and perpendicular to that of the plane-polarized transmit pulse at 532 nm (green) and 1064 nm (near IR), for both the active laser backscatter retro-reflectance and the passive solar bi-directional reflectance. The active and passive data provide distinct, but complimentary, measurements that have the potential to differentiate target types. Key to that differentiation is the wavelength-dependent degree of backscatter depolarization that is a measure of the amount of multiple-scattering. In the case of forest cover, this is related to the reflectance, size and spatial organization of foliage and branch components. The 2010 SIMPL data collection includes the Smithsonian Environmental Research Center, MD and New Jersey Pine Barrens study sites being used for ICESat-2 algorithm development purposes. In 2011, during the Eco-3D airborne campaign aboard NASA’s P-3 aircraft, SIMPL, DBSAR (Digital Beamforming Synthetic Aperture Radar) and CAR (Cloud Aerosol Radiometer) data was acquired for a variety of forest sites extending from Quebec to Florida. Example data products illustrate SIMPL’s measurements for several sites with distinct canopy structures and compositions. Presentation Type: Poster Session: Other (Mon 4:00 PM) Associated Project(s):
Poster Location ID: 33
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