ECOSAR THE FIRST P- BAND DIGITAL BEAMFORMING POLARIMETRIC INTERFEROMETRIC SARINSTRUMENT 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 DESCRIPTIONP-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 BeamformingEcoSAR will fly on the NASA P3airplane based at Wallops FlightFacility
MAIN SCIENCE OBJECTIVESEcoSAR 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 Earths carbon cycle and ecosystems changing, and what are the consequences for the Earths 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 recentdisturbance 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 (R2 = 0.9)P-Band SAR Measures Boreal & temperate ForestBiomass up to 200 Mg/ha with ±10% Accuracy Saatchi & Moghaddam, 2000
AirSAR P-Band SAR Measurement of Tropical ForestDisturbance 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 HHVscatteringphasecenterHHscatteringphasecenter
Example of SAR and InSARusing DBSAR (L-band) measurements Height (m)
Schedule and Milestones Year 1Definition of the EcoSAR science and system and requirementsAntenna Arrays Design and fabricationRadar Electronics Unit Design and fabrication Year 2Completion of Waveform generator/data systemTesting and programming of waveform generator/data systemRadar Electronics evaluation, testing and initial assembly.Full system integration and testing in laboratory and in anechoic chamber. Year 3Installation and test flight operation of the system on the NASA P-3 aircraftValidation of EcoSAR test flight data setsField Campaign 1 New Hampshire and MaineField Campaign 2 Costa RicaScience Retrievals from EcoSAR campaigns
FIELD CAMPAIGNSNew England Summer 2013 Costa Rica Winter 2014 + Wallops & SERC
CURRENT STATUS• Successfully completed the design of prototype dual polarized widebandP-band antenna element.• Simulations of Full array performance is underway.• Preliminary Aerodynamic analysis on antenna structure has beenperformed.• 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.