ECE Seminar or Event

Electromagnetic Models in Active and Passive Microwave Remote Sensing of Snow Water Equivalent and Soil Moisture

Leung Tsang

U. of Washington, Dept. of Electrical Engineering
Monday, February 25, 2013
1:00pm - 2:30pm
1005 EECS

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About the Event

We describe the electromagnetic models that have been applied to active and passive microwave remote sensing of soil moisture and snow water equivalent. For soil moisture, the notable upcoming satellite mission is the NASA SMAP (Soil Moisture Active and Passive) mission. SMAP is one of the first-tier missions recommended by the Decadal studies and is scheduled to be launched in October 2014. For snow water equivalent, there are two satellite missions, the CoREH2O (Cold Regions Hydrology High-Resolution Observatory) and the SCLP (Snow Cold Land Process), that are being considered respectively by the European Space Agency and NASA. In microwave scattering by terrestrial snow, snow is considered a dense medium with densely packed inhomogeneities. We describe the work of dense media radiative transfer theory that incorporate coherent effects of scattering by densely packed particles. Three approaches have been used, (i) the analytical theory of the quasicrystalline approximation and correlated ladder approximation, (ii) the Foldy Lax multiple scattering equations, and (iii) the bicontinuous media model with discrete dipole approximation. Results of frequency and polarization dependence of dense media scattering are illustrated and compared with experimental data of measurements on terrestrial snow. In the interactions of microwaves with vegetated surface, the microwave signatures are determined by scattering of electromagnetic waves by random rough surfaces and the vegetation canopy. The random rough surfaces are characterized by Gaussian random process with exponential correlation functions. Numerical solutions of Maxwell equations are calculated using Method of Moments, accelerated by the UV/PBTG/SMCG method. Computed results of backscattering of co-polarization and cross polarization are compared with experiments. Physical models for the VV, HH and HV backscattering, taking into account the effects of rough surface, volume scattering and double bounce, have been tabulated for a variety of vegetated surfaces. Results have been validated against ground measurements taken at SMAP core validation sites.


Leung Tsang received the Ph.D. degree from the Massachusetts Institute of Technology. He has been a Professor of Electrical Engineering at the University of Washington since 1983 and was the Chair of the Department in 2006-2011. He was the President of IEEE Geoscience and Remote Sensing Society in 2006-2007 and the Editor-in-Chief of the IEEE Transactions on Geoscience and Remote Sensing in 1996-2000. He is the co-author of 4 books: Theory of Microwave Remote Sensing (Wiley-Interscience, 1985), Scattering of Electromagnetic Waves, vols. 1, 2 and 3. (Wiley Interscience, 2000, 2001). He received the Pecora Award (cosponsored by Department of Interior (USGS) and NASA) in 2012, and the IEEE Electromagnetics Award in 2013.

Additional Information

Contact: Linda Scovel


Sponsor(s): Electrical and Computer Engineering

Open to: Public