EcoSAR First Results - ESA SEOMseom.esa.int/polinsar-biomass2015/files/D4S2_P-Band... · 2015. 2....

BIOMASS 1st Science Workshop 27-30 January 2015

EcoSAR First Results

Lola Fatoyinbo, Rafael F. Rincon, K. Jon Ranson, Batuhan Osmanoglu, Guoqing Sun, Seung Kuk Lee


EcoSAR EcoSAR is a new airborne radar developed at NASA/Goddard Space Flight Center for the measurements of terrestrial ecosystem structure and biomass funded through the 2010 Instrument Incubator Program:

• Acquires P-band InSAR measurements of vegetation structure and biomass in order to quantify carbon storage, sequestration and emissions in terrestrial vegetation.

• Employs Electronic Beam Steering and Digital Beamforming to implement Polarimetric and Interferometric Synthetic Aperture Radar (SAR).


Science Objective to measure forest biomass and structure in high biomass forests • Polarimetric • Long wavelengths • Dual-antenna system for single pass InSAR


We need to image as large and area as possible with the finest resolution:

• Wideband Digital Beamforming

• Large Bandwidth


Center Frequency 435 MHz Pulse Length 1 usec – 50 usec

Maximum Bandwidth 200 MHz Array Peak Power 40 Watts

Polarization HH, VV, VH,HV PRF 100 Hz – 10 KHz

Polarization Isolation > 30 dB Swath 4 km – 8 km

Noise Equivalent o - 41 dB * Finest Range Resolution 0.75 m

Total Number of active Channels 32 Single Look Azimuth Resolution 0.5 m

Interferometric baseline 25 m Vertical Accuracy ~ 1 m

Main Parameters


Other Applications

• Snow/Permafrost/Freeze/Thaw state

• Soil Moisture/ Surface water

• DEM/Surface Topography/Deformation


Instrument Heritage: DBSAR L-band

Swath 3

Flight Path

Swath 4

rx

rx

ry

ry

θ3

θ4

Total Sawth Left

Antenna

Swath 2

Swath 1

rx

ry

rx

ry

Total Sawth Right

θ2

θ1

Flight Path

Antenna

θ3

θ2

θ1

θ4

θN+1θN

h

Flight Path

Antenna

Flight'Path'

Synthetic Aperture Radar: • implement non-conventional SAR

techniques that increase coverage and avoid ambiguities such as the simultaneous left and right imaging.

• Applicable to Ecosystem structure, geodesy of the Earth, planets, and asteroids.

Scatterometry: • Over multiple beams and over a wide

range of incidence angles. • Measures roughness and dielectric

properties of surfaces applicable to the study of soil moisture and ocean salinity.

• Onboard scatterometry over 32 beams (right plot) has been demonstrated in airborne flights.

Altimetry: • altimeter measurements using SAR

processing methods on the nadir beam. • can be implemented simultaneously with

the SAR operation without rotating the antenna.


DBSAR Digital Beamforming SAR • Ecosystem-3D campaign in 2011 and 2012

H H V V V H H V

DBSAR SAR data over Howland, Maine

1

2 3

4

5 6

7

8


Biomass (Mg/ha)

DBSAR HV ( ), UAVSAR HV( )

DBSAR’s Biomass Estimates

Comparison between DBSAR and UAVSAR polarimetric backscatter using RGB composite (left) and biomass estimates (right). The biomass data was obtained from 11 1-ha (50m x 200m) plots within the imaged area.

HV


On board Processor/RAIDS

EcoSAR system

Transceiver


Flight Campaigns


Andros Island


Costa Rica

La Selva

Terraba Sierpe

Corcovado NP


Sierpe Wetlands


Corcovado Rainforest


Canopy Biomass Lidar CBL


EcoSAR Synergies with BIOMASS

• Become instrument for BIOMASS cal/val activities

• Become multi-mission simulator: can fly L-, P and Lidar(s) simultaneously


Conclusions

• EcoSAR sensor development was a success and was able to fulfill its measurement objectives.

• EcoSAR acquired large amounts of airborne data over high biomass forest areas (incl. supersites)

• EcoSAR team is producing the L 0 & L1 data products and will make them available

• All field measurements will also be made available

• We’re continuing to work on producing canopy height & Biomass products

• EcoSAR team is looking forward to collaboration with BIOMASS


www.EcoSAR.gsfc.nasa.gov (coming soon)


HH HV

EcoSAR 50 MHz Imagery


RFI Measurements

MHz

MHz

Spectrum with onboard 50 MHZ Digital Filter

• RFI measurements were acquired at each location in sniffing mode.

• The RFI present during the EcoSAR measurements affects image focusing and reduces image quality.

• Despite the on board filtering and large coherent signal-processing gain of the SAR processing, RFI remains in the focused image.

• Our team is working on the development of robust RFI detection and removal.

Spectrum without onboard Digital Filtering


Concluding Remarks and Future Plans • EcoSAR measurements are crucial for future SAR missions

validation (DESDynI/NI-SAR, BIOMASS, Tandem-L)

• Improved Carbon and forest structure estimates will support international C reduction initiatives (UN REDD/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?


Outline

• Motivation for the design of the instrument

• Instrument Heritage

• System specifications and parameters

• Flight and field campaigns

• First results

• Conclusions and future steps


Measurement

Level 1 Requirements Level 2 Requirements EcoSAR instrument

requirement Resolution Accuracy Coverage Method Product Resolution Coverage

Biomass 1m -10 m 20% or 20

Mg/ha for areas >100 Mg/ha

Areas of woody biomass

Pol-InSAR

10-100m

Mixed Dry Forest Single Pass Interferometry

InSAR Tropical Rainforest Full Polarimetry (HH, VV, HV, VH)

Polarimetry Mangrove Wetlands Cross pole isolation >25 dB

Swath > 2km

Canopy structure 1m -10 m 1 m

Canopy heights representative of high biomass forest (ie. Tropical rainforest)

InSAR

10-100m

Mixed Dry Forest Single Pass Interferometry

Pol-InSAR Tropical Rainforest Full Polarimetry (HH, VV, HV, VH)

Mangrove Wetlands Swath > 2km

Ecosystem extent 1m -10 m 80% for areas losing >50 % canopy cover

Forested and wetland areas

80% or better classification accuracy

10-100m

Mixed Dry Forest Full Polarimetry (HH, VV, HV, VH)

Tropical Rainforest Cross pol isolation >25 dB

Mangrove Wetlands 1m-30 m Resolution

Swath > 2km

Human activity

1m -10 m 80% for areas losing >50 % canopy cover

Secondary Forest

80% or better classification accuracy

10-100m

Agricultural areas P-band PolSAR

Disturbance Degraded Areas Forest Regeneration Cross pole isolation >25 dB

Recovery Clear Cuts 1m-30 m Resolution

Agricultural areas

Swath > 2km

Science Requirements


EcoSAR

• Airborne SAR system

• Single-pass interferometer

• Images multiple tracks without losing resolution

• Fully polarimetric


Wideband Digital Beamforming

EcoSAR First Results - ESA SEOMseom.esa.int/polinsar-biomass2015/files/D4S2_P-Band... · 2015. 2....

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