SAR, InSAR and Lidar Studies for Measuring Vegetation Structure over the Harvard Forest
Paul
Robert
Siqueira, University of Massachusetts, siqueira@ecs.umass.edu
(Presenting)
Razi
Ahmed, University of Massachusetts, ahmed@mirsl.ecs.umass.edu
Scott
Hensley, Jet Propulsion Laboratory, sh@radar-sci.jpl.nasa.gov
Bruce
Chapman, Jet Propulsion, Laboratory, bruce.chapman@jpl.nasa.gov
Kathleen
Bergen, University of Michigan, kbergen@umich.edu
Located near the Quabbin reservoir in Western Massachusetts, the Harvard Forest is a temperate zone mixed phase forest consisting of a variety of transition hardwood regrowth resulting from widespread disturbances that took place over 100 years ago. One of the nine NASA funded Bigfoot sites for connecting remote sensing measurements to ground process observations of carbon flux and net primary production, the Harvard Forest has been a resource for a wide variety of ecological studies on spatial scales extending from the microscopic to macroscopic. Typical characteristics of the region that are relevant to this study are an upper limit to carbon content range between 100 and 120 Mg/ha, an average height of 24m, a mean basal area of 40 m2/ha, and on the order of 1000 trees/ha.
In July of 2003, the Laser Vegetation Imaging Sensor (LVIS) overflew the Harvard region, collecting full waveform lidar data for determining the true ground elevation and the vertical extent of the canopy over a 30 kha area (9 km x 30 km). Through a coordinated effort with the Japanese Space Agency (JAXA) and the Kyoto and Carbon Cycle Initiative , since the launch of the ALOS satellite in 2006, the Harvard Forest has been the focus of many fully polarimetric, and single/dual-pol L-band observations separated by a 46 day repeat cycle. This rich and consistent data set, unprecedented even under the ALOS observing strategy, provides an opportunity to explore relationships between a wide variety of spatial and temporal interferometric baselines, an extensive time series of single-, dual- and quad-pol backscatter observations, and the LVIS lidar data, to better understand methods of combining these fundamental data sources for studying the ecosystems, carbon balance and vegetation three-dimensional structure. A careful set of steps are executed to process the raw SAR data into a differential interferogram which takes into account surface topography and slope effects. Once images are co-located to a geographic reference, they may be compared with other data sources for better understanding and exploring the desired vegetation signature.
NASA Carbon Cycle & Ecosystems Active Awards Represented by this Poster: