|KURUM, MEHMET - National Aeronautics And Space Administration (NASA)|
|O'NEILL, PEGGY - National Aeronautics And Space Administration (NASA)|
|LANG, ROGER - George Washington University|
|JOSEPH, ALICIA - National Aeronautics And Space Administration (NASA)|
Submitted to: International Geoscience and Remote Sensing Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 8/11/2010
Publication Date: 10/22/2010
Citation: Kurum, M., O'Neill, P.E., Lang, R.H., Joseph, A.T., Cosh, M.H., Jackson, T.J. 2010. Characterization of forest opacity using mulit-angular emission and backscatter data. In: Proceedings of the International Geoscience and Remote Sensing Symposium, July 25-30, 2010, Honolulu, Hawaii. III:2051-2054.
Technical Abstract: This paper discusses the results from a series of field experiments using ground-based L-band microwave active/passive sensors. Three independent approaches are employed to the microwave data to determine vegetation opacity of coniferous trees. First, a zero-order radiative transfer model is fitted to multi-angular microwave emissivity data in a least-square sense to provide “effective” vegetation optical depth. Second, a ratio between radar backscatter measurements with the corner reflector under trees and in an open area is calculated to obtain “measured” tree propagation characteristics. Finally, the “theoretical” propagation constant is determined by forward scattering theorem using detailed measurements of size/angle distributions and dielectric constants of the tree constituents (trunk, branches, and needles). The results indicate that “effective” values underestimate attenuation values compared to both “theoretical” and “measured” values.