Saatchi, Sassan: Jet Propulsion Laboratory / Caltech (Project Lead)
Project Funding:
2006 - 2009
NRA: 2005 NASA: Remote Sensing Science for Carbon and Climate
Funded by NASA
Abstract:
Currently two active remote sensing technologies, the P-band (70 cm wavelength) synthetic aperture radar (SAR) and the full-waveform lidar sensors, provide the most promising techniques for a globally consistent measurement of forest above-ground biomass (AGB) and 3-D structure. These measurements are considered crucial in quantifying the magnitude of terrestrial carbon pool, its horizontal and vertical distribution, and its changes as a result of disturbance and recovery. When provided from a space-based platform, the measurements will allow us, for the first time, to quantify key variables in understanding the function of the earth’s vegetation cover in terms of carbon cycling, its role as sources and sinks of atmospheric CO2, and its patterns of biological diversity and richness on a global scale. However, there are several key questions regarding the spatial and temporal resolutions, the accuracy of the measurements, the synergism of the techniques, and how they can be used in quantifying the ecosystem function that must be addressed before such technology is implemented for a spaceborne application. We propose to study the fusion of lidar and radar for measuring forest biomass and the 3-D structure along with ecosystem modeling in order to perform a tradeoff study between the science requirements for measuring regional carbon stock and fluxes and measurement characteristics. The proposed work will use existing data from airborne sensors over three sites representing forests with different structure and biomass to address the following questions: 1. To what extent structural variables measured by two instruments independently and in a fusion approach complement or improve the accuracy of 3-D forest structure and biomass? 2. How the lidar sampling and radar imaging can be combined to provide the spatial resolution and structural heterogeneity required for assessing regional carbon stock and dynamics? 3. What are the required measurement characteristics and science tradeoffs for a spaceborne mission concept combining the two active instruments? This proposed work responds to the science goals of the NASA terrestrial ecology program and carbon cycle roadmap. Specifically, the objectives of this proposal are directed towards the guidelines of the ROSES announcement by addressing the biophysics of remote sensing of terrestrial ecosystems and focusing on evaluation, inter-comparison and synergism of two most-promising technologies for terrestrial carbon cycle. By incorporating the remote sensing measurements into an ecosystem demography model (ED) working at scales comparable to remote sensing measurements and regional carbon cycle, the tradeoff between science requirements and measurement characteristics in terms of accuracy, spatial and temporal resolutions will be quantified.
2013 NASA Terrestrial Ecology Science Team Meeting Poster(s)
- Forest Disturbance Spectrum of the Amazon Forest
-- (Fernando Espírito-Santo, Michael Keller, Manuel Gloor, Yadvinder Malhi, Sassan Saatchi, Michael Palace, Steve Frolking, Oliver Phillips)
[abstract]
2011 NASA Carbon Cycle & Ecosystems Joint Science Workshop Poster(s)
- Impact of Spatial and Temporal Variability of Tropical Forest Structure on LIDAR Estimation of Aboveground Biomass
-- (Victoria Meyer, Sassan Saatchi, Geoffrey Andrew Fricker, Jerome Chave, Maxim Neumann)
[abstract]
- Remote Sensing Derived Estimates of Forest Structure and Composition
-- (Paul R. Moorcroft, Alexander Antonarakis)
[abstract]
- Land use change exacerbates tropical South American drought by sea surface temperature variability
-- (Jung-Eun Lee, Benjamin R Lintner, C Kevin Boyce, Peter J Lawrence)
[abstract]
- Mapping Global Forest Carbon Stock
-- (Yifan Yu, Sassan Saatchi, Ulrike Seibt, Michael Lefsky)
[abstract]
More details may be found in the following project profile(s):