ECOSAR THE FIRST P- BAND DIGITAL BEAMFORMING POLARIMETRIC INTERFEROMETRIC SAR INSTRUMENT TO MEASURE ECOSYSTEM STRUCTURE, BIOMASS, AND SURFACE WATER GSFC Science Temilola Fatoyinbo Jon Ranson Guoqing Sun GSFC Engineering Rafael Rincon Manohar Deshpande Martin Perrine Quenton Bonds Matthew Mclinden External Partners Richard Hale (University of Kansas) Intelligence Automation Inc. ESTO-IIP 2011-2014
ECOSAR SYSTEM DESCRIPTION P-band Digital Beamforming Polarimetric Interferometric SAR: Dual Antennas with 25 m baseline • Center frequency of 435 MHz (69 cm wavelength) • Range resolution (8 m – 44 m) • High resolution science mode (1.3 m) • Polarization HH, VV, HV, VH • Digital Beamforming • EcoSAR will fly on the NASA P3 airplane based at Wallops Flight Facility
MAIN SCIENCE OBJECTIVES EcoSAR instrument will quantify: Biomass (up to 200 Mg/ha from Polarimetric SAR) • Canopy and Surface Height ( 1m accuracy from PolInSAR) • Ecosystem structure and extent (range resolution of 1.3 m) • Disturbance and recovery •
SCIENCE OBJECTIVES • These measurements are crucial for future SAR mission validation (DesdynI, BIOMASS, Tandem-L) • Improved Carbon and forest structure estimates will support international C reduction initiatives (REDD+) • How are the Earth's carbon cycle and ecosystems changing, and what are the consequences for the Earth's carbon budget, ecosystem sustainability, and biodiversity?
WHY P-BAND • Longer wavelengths (L- and P- band) are able to penetrate the canopy and are scattered by larger components, such as the trunk and the ground and thereby increase the returned signal. P-Band (HH,HV,VV) Dark areas in this image are recent disturbance from logging.
P-Band Measurements of Boreal & Temperate Forest Biomass P-Band (HH,HV,VV) L-Band (HH,HV,VV) C-Band (HH,HV,VV) 200 Field Stem Biomass (tons/ha) P-band Algorithm R=0.954 150 100 50 Saatchi & Moghaddam 2000 0 0 50 100 150 200 SAR Predicted Stem Biomass P-Band Estimated Forest Stem Biomass vs Field measurements in Boreal Forests (R 2 = 0.9) P-Band SAR Measures Boreal & temperate Forest Saatchi & Moghaddam, 2000 Biomass up to 200 Mg/ha with ± 10% Accuracy
AirSAR P-Band SAR Measurement of Tropical Forest Disturbance and Aboveground Biomass (HH, HV, VV) AirSAR P-band Image (1993) Manu National Park, Peru
Pol-InSAR height measurements: Polarization is sensitive to scattering • mechanisms with different interferometric scattering phase centers EcoSAR will allow us to separate ground signal • from canopy signal and derive canopy height. HV H H HV scattering phase center HH scattering phase center
Example of SAR and InSAR using DBSAR (L-band) measurements Height (m)
EcoSAR Concept
EcoSAR + DBSAR
Schedule and Milestones Year 1 Definition of the EcoSAR science and system and requirements Antenna Arrays Design and fabrication Radar Electronics Unit Design and fabrication Year 2 Completion of Waveform generator/data system Testing and programming of waveform generator/data system Radar Electronics evaluation, testing and initial assembly. Full system integration and testing in laboratory and in anechoic chamber. Year 3 Installation and test flight operation of the system on the NASA P-3 aircraft Validation of EcoSAR test flight data sets Field Campaign 1 New Hampshire and Maine Field Campaign 2 Costa Rica Science Retrievals from EcoSAR campaigns
FIELD CAMPAIGNS New England Summer 2013 Costa Rica Winter 2014 + Wallops & SERC
CURRENT STATUS • Successfully completed the design of prototype dual polarized wideband P-band antenna element. • Simulations of Full array performance is underway. • Preliminary Aerodynamic analysis on antenna structure has been performed. • Several radar transceiver designs have been formulated and evaluated. Components specifications and availability are being investigated. • Waiting for contract to IAI to begin processor development.
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