Project Funding: 2006 - 2009

NRA: 2005 NASA: Remote Sensing Science for Carbon and Climate   

Funded by NASA

Abstract:
Interferometric synthetic aperture radar (InSAR) has great potential to meet NASA's 3-dimenionsal (3-D) vegetation structure goals called out in the Carbon Cycle and Ecosystems Roadmap and this NRA. NASA demonstrated InSAR profiling capability in boreal forests in Oregon, but it is especially important to develop 3-D remote sensing capabilities in tropical forests, which contain 45% of the Earth's forest biomass. The two broad objectives of this proposal are therefore: 1) To characterize the limiting accuracy of vertical profiling and consequent biomass estimation with InSAR in tropical forests; and 2) to develop methodology to optimize profile and biomass accuracy from multiple InSAR data sets acquired in Amazônian tropical forests. The first broad objective entails estimating and validating vertical vegetation profiles from an unprecedented data set of 16 fixed InSAR baselines and 2 frequencies over 25 1-hectare sites at La Selva Biological Station in Costa Rica, taken in March 2004. The second objective entails producing profiles and biomass estimates from multiple-frequency airborne InSAR +SRTM data sets over 25 sites at Tapajós National Forest in Para, Brazil from 2000. A more extensive 20 x 12 km structure and biomass map will be derived from SRTM alone. The methodology of the proposal first establishes limiting errors in La Selva profiles for primary, secondary, and selectively logged forest stands by comparing to lidar- and field-derived profiles. Biomasses estimated from functions of these profiles will be compared to lidar- and field-derived biomasses. An important part of remote sensing science is to develop systematic approaches to optimizing more restricted, operational data sets than the extensive one available at La Selva. A set of La Selva-derived InSAR constraints will therefore be applied to multiple frequency Tapajós data to optimize its profiling potential. Quantitative physical modeling of the scattered electromagnetic radiation received by InSAR sensors will support broad conclusions informing NASA's future technology development choices about 3-D monitoring. Consistent with NASA's strategic objectives, the 2 objectives of this proposal demonstrate "new technologies with the potential to improve future operational systems." This work also responds to the national goal to "promote international and commercial participation in exploration." With the Brazilian remote sensing, it is also relevant to NASA's Large Scale Biosphere-Atmosphere Experiment (LBA).

Publications:

Treuhaft, R., Gonzalves, F., dos Santos, J. R., Keller, M., Palace, M., Madsen, S. N., Sullivan, F., Graca, P. M. L. A. 2015. Tropical-Forest Biomass Estimation at X-Band From the Spaceborne TanDEM-X Interferometer. IEEE Geoscience and Remote Sensing Letters. 12(2), 239-243. DOI: 10.1109/LGRS.2014.2334140

2013 NASA Terrestrial Ecology Science Team Meeting Poster(s)

• Tropical Forest Structure and Biomass Estimation from Bistatic InSAR at X-band (TanDEM-X), Small-Spot Lidar, and Field Measurements in the Amazonian Basin   --   (Robert Neil Treuhaft, Fabio G. Goncalves, Joao Roberto dos Santos, Soren Madsen, Michael Palace, Michael Keller, Scott Hensley)   [abstract]

2010 NASA Terrestrial Ecology Science Team Meeting Poster(s)

• Estimating Tropical-Forest Biomass from the Fourier Transform of Lidar or InSAR Profiles: Improved Performance and a Paradigm for Lidar-InSAR DESDynI Fusion   --   (Robert Treuhaft, Fabio Gonçalves, Jason Drake, Bruce Chapman, João Roberto dos Santos, Luciano Dutra, Paulo Graça, George Purcell)   [abstract]

2008 NASA Carbon Cycle & Ecosystems Joint Science Workshop Posters

• Comparing Tropical Vegetation Structure from Interferometric SAR at C-band, Field Measurements, and Lidar   --   (Robert Treuhaft, Bruce Chapman, Fabio Gonçalves, Joao Roberto dos Santos, Luciano Dutra, Paulo Alencastro Graça, Jason Drake)   [abstract]

More details may be found in the following project profile(s):

• NASA Terrestrial Ecology (TE) Project Profile