UAVSAR airborne L-band radar campaign over boreal, temperate and tropical forests
Marc
Simard, Caltech/Jet Propulsion Laboratory, marc.simard@jpl.nasa.gov
(Presenting)
Naiara
Pinto, NASA (NPP)/ JPL, naiara.pinto@jpl.nasa.gov
Ralph
Dubayah, University of Maryland, dubayah@gmail.com
Scott
Hensley, Caltech/Jet Propulsion Laboratory, scott.hensley@jpl.nasa.gov
We present the first results of the 2009-2010 UAVSAR and field campaigns over boreal, temperate and tropical forests. UAVSAR is a new L-band fully polarimetric synthetic aperture radar (inSAR) capable of repeat pass interferometry. The UAVSAR campaigns were designed to inform the upcoming NASA's DESDynI mission to estimate vegetation 3D structure and biomass, and specifically, to quantify the impact of temporal changes on the radar measurement.
Temporal changes occur mainly as a result of precipitation and changes in wind strength between radar acquisitions. To achieve this, UAVSAR collected data several times over 5 sites within a 13-day period. This enabled analysis of backscatter changes within a set of time intervals. Weather data was collected during the entire flight campaign and used to identify potential spatial pattern of change in the radar data. We also collected field data on vegetation 3D structure in 90 plots with a range of forest and structure types in Québec, New Hampshire, Maine and Costa Rica.
In this project, we developed a radiometric calibration algorithm which is necessary to estimate biomass using polarimetric backscatter. There are 2 main radiometric effects to be corrected: variations in topography and change of canopy reflectivity with incidence angle. While the efficiency of the former algorithm strongly depends on the DEM accuracy, the latter depends on vegetation type. We show the polarimetric calibration curves for each land cover type and present a generalized solution for radiometric calibration of L-band polarimetric data. Finally we present preliminary results of canopy height and biomass estimates at the landscape scale.
Presentation Type: Poster
Poster Session: Field Campaigns
NASA TE Funded Awards Represented:
Simard, Marc
3D Vegetation Structure using L-band InSAR and Lidar