Wednesday 22 April 2009

1-2pm, in Fenner School's Forestry Lecture Theatre

Advanced Analysis of Vegetation Using Imaging Spectrometry

Professor Dar Roberts, Department of Geography, U.C. Santa Barbara

Abstract

Imaging spectrometers acquire reflected or emitted radiance in a large number of contiguous wavelengths. Most commercial and public imaging spectrometers sample electromagnetic radiation between 350 and 2500 nm, covering the visible, near-infrared (VNIR) and short-wave infrared (SWIR) portions of the spectrum. This spectral region provides detailed spectroscopic information critical for improved atmospheric correction and reflectance retrievals required for monitoring surface changes. Furthermore, the VNIR-SWIR provides numerous diagnostic spectroscopic features required to identify material chemistry in solid, liquid and vapor phases. Examples include important plant bio-chemicals, including plant pigments, water and structural compounds such as lignin and cellulose. At the canopy and landscape scales, imaging spectrometers provide improved biophysical measures including leaf area index, plant composition and cover. To the extent to which plant species have unique biochemical and structural properties, and thus unique spectra, these can be used to map species using imaging spectrometry.

In this talk, I provide an overview of research using the Airborne Visible Infrared Imaging Spectrometer (AVIRIS) to retrieve important biophysical properties, monitor plant stress and identify vegetation species. I start with a general discussion of atmospheric correction and reflectance retrievals. Next, I discuss the use of AVIRIS to map canopy water, estimate leaf area index and map plant stress using narrow-band spectral indices. I follow with examples using AVIRIS to map plant species in several ecosystems. I conclude with a discussion of the potential of proposed future space-borne imaging sensors.     

Bio

Photo: www.geog.ucsb.edu

Dr Dar Roberts is a professor in the Department of Geography at U.C. Santa Barbara, where he started in January, 1994. His primary research interests are in remote sensing of vegetation, land-cover change, fire danger, spectroscopy, urban remote sensing and trace gas mapping using imaging spectrometry.  He has worked extensively with optical remote sensing in the visible, near-infrared and thermal infrared and active remote sensing, including radar and lidar. He has authored or co-authored over 210 publications including 90 in the refereed literature. He teaches classes in graduate level remote sensing, environmental optics, environmental data analysis and historical geography. He has played a lead role in algorithm development, most notably Viper Tools. He is currently on sabbatical at CSIRO in Perth, in part supported by the CSIRO McMaster Research Fellowship.

The Fenner School Seminar Series is held in the Forestry Lecture Theatre, Forestry Building 48, Linnaeus Way (comes off Daley Road), ANU (Acton) campus, ACT

The seminar will start at 13:00 and finish at 14:00