The BioElectromagnetics of Tropical Forests: Culling Simplicity from Spatio-Temporal Confusion

Friday, May 9, 2014 - 2:00pm
Fung Auditorium | Powell-Focht Bioengineering Hall
Robert Treuhaft

Principal Member, Technical Staff 

Jet Propulsion Laboratory

The BioElectromagnetics of Tropical Forests: Culling Simplicity from Spatio-Temporal Confusion

Tropical forests account for 50% of the world’s forested biomass. Tropical-forest deforestation accounts for about 15% of anthropogenic contributions to atmospheric carbon. Global carbon-cycle accounting and concomitant studies of global warming require global biomass measurements on sub hectare (104 direct measurement of biomass would use the force of gravity to directly “weigh” the forest. But the remote sensing of forests from space instead uses the electromagnetic force. It involves sending an electromagnetic wave down to the forest, where it interacts with forest biological components—leaves, branches, and trunks—and carries the signature of those interactions back up to space via the scattered electromagnetic wave. This talk describes electromagnetic scattering and statistical modeling used to convert the signals from 1000’s of scattering events in forest canopies into a few structural parameters. It then proposes biophysical modeling as a means to associating derived structural parameters with biomass and other forest characteristics.

Robert Treuhaft grew up in New Jersey and did his undergraduate work at Yale University (1976) in physics. He pursued a PhD (1982) in physics at UC Berkeley in high-energy nuclear interactions. He joined the Jet Propulsion Laboratory in 1982, and is currently Principal Member of Technical Staff. First projects at JPL were in Very Long Baseline Interferometry (VLBI), for which he developed a model of atmospheric turbulence published in 1987, still in use today. He then used this model to perform the first measurement of relativistic deflection (ray bending) by a planet (Jupiter), predicted by Einstein in 1905, measured by Treuhaft and Lowe (JPL colleague) in 1988, and published in 1991. In 1993, Treuhaft began research in the radar remote sensing of forests. Principal papers on how to use interferometric SAR for forest remote sensing appeared in 1996 and 2000. He established a Brazilian collaboration for tropical forest work in the mid 2000’s, learned Portuguese, and in 2009 he published (with Brazilians) a paper on comparison of laser ranging, interferometric SAR, and field-determined forest structure in Costa Rica. Recent work involves tropical forests in Brazil observed with the German TanDEM-X interferometer. In addition to forest remote sensing, in 1999, Treuhaft participated in the first cm-level measurement of the altitude of a body of water (Crater Lake) using GPS-reflected signals, published in 2001. Treuhaft also taught as an adjunct professor of physics at Harvey Mudd, 2007-2009. He has produced 3 rock CDs in his home studio, and took up the trumpet in 2007. He plays in two jazz bands.