TropiSCAT : A MULTI-FREQUENCY POLINSAR DATA CAMPAIGN OF ACQUISITION FOR VEGETATION CHARACTERIZATION Clément ALBINET – Office National d’Etudes et de Recherches Aérospatiales (ONERA) Pierre BORDERIES – Office National d’Etudes et de Recherches Aérospatiales (ONERA) Thierry KOLECK – Centre National d’Etudes Spatiales (CNES) Fabio ROCCA – Politecnico di Milano (POLIMI) Stefano TEBALDINI – Politecnico di Milano (POLIMI) Thuy LE TOAN – Centre d’Etudes Spatiales de la BIOsphère (CESBIO) Ludovic VILLARD – Centre d’Etudes Spatiales de la BIOsphère (CESBIO) Stéphane MERMOZ – Centre d’Etudes Spatiales de la BIOsphère (CESBIO) Dinh HO TONG MINH – Politecnico di Milano (POLIMI) IGARSS 2011 VANCOUVER – Tuesday, July 26 – TU4.T05 SAR/Lidar Sensing

BIOMASS Mission, candidate for the ESA 7 th Earth Explorer Mission First Synthetic Aperture Radar (SAR) at P-band 3 Introduction and Context Forest with high biomass density (>300ton/ha) → PolInSAR  High temporal coherence is necessary ! → Airborne experiment : TropiSAR (2009) → Ground based experiment : TropiSCAT (ESA and CNES founding)

IGARSS 2011 VANCOUVER – Tuesday, July 26 – TU4.T05 SAR/Lidar Sensing Introduction and Context 1. Experiment description 2. Preliminary campaign results 3. TropiSCAT first results 4. TropiSCAT development Conclusion 4 Plan

IGARSS 2011 VANCOUVER – Tuesday, July 26 – TU4.T05 SAR/Lidar Sensing 5 1. Experiment description Goal : Polarimetric intensity Polarimetric complex coherence Polarimetric vertical imaging (tomography) Time scales : Minutes Daily Monthly Yearly

IGARSS 2011 VANCOUVER – Tuesday, July 26 – TU4.T05 SAR/Lidar Sensing 6 1. Experiment description Equipment : VNA – Agilent A5061B : With IF=1kHz, noise is less than -100 dBm. Antennas – SATIMO LP400 : 400MHz – 1GHz Adequate 3dB aperture : E - 50° / H - 65°. RF Switches : Solid state switches. 70m Low loss cables : Losses measured in laboratory range from 3 dB at 400 MHz to 5 dB at 1 GHz. Industrial Computer : Compact design Tropicalized motherboard Waterproof

IGARSS 2011 VANCOUVER – Tuesday, July 26 – TU4.T05 SAR/Lidar Sensing Location - Requirements : High biomass density High number of different tree species High spot for radar measurement Safe place for hardware → Guyaflux tower in Paracou, French Guiana 7 1. Experiment description

IGARSS 2011 VANCOUVER – Tuesday, July 26 – TU4.T05 SAR/Lidar Sensing Location : 55 m high Guyaflux tower in Paracou, French Guiana 8 1. Experiment description  Primary forest  Continuously studied since the seventies  Ground data are continuously collected (weather, soil moisture, tree measurements)  Test site overflown by TropiSAR campaign (ONERA, August 2009) view from the top of the tower :

IGARSS 2011 VANCOUVER – Tuesday, July 26 – TU4.T05 SAR/Lidar Sensing 9 2. Preliminary experiment results Project evolution/planning : October 2010 – Preliminary campaign with light equipment. June 2011 – Setup of the automatic full-polarimetric backscattering and coherence measurements. September Setup of the automatic tomographic measurements. Instrument architecture : 2 moving antennas Direct measurements  To demonstrate the feasibility of the concept

IGARSS 2011 VANCOUVER – Tuesday, July 26 – TU4.T05 SAR/Lidar Sensing Preliminary experiment results Intensity :  Validation of impulses responses

IGARSS 2011 VANCOUVER – Tuesday, July 26 – TU4.T05 SAR/Lidar Sensing Preliminary experiment results  Validation of tomograms Vertical tomography :

IGARSS 2011 VANCOUVER – Tuesday, July 26 – TU4.T05 SAR/Lidar Sensing Preliminary experiment results HH HV VV Vertical tomography :  Localization of the contributors

IGARSS 2011 VANCOUVER – Tuesday, July 26 – TU4.T05 SAR/Lidar Sensing TropiSCAT first results Project evolution/planning : October 2010 – Preliminary campaign with light equipment. June 2011 – Setup of the automatic full-polarimetric backscattering and coherence measurements. September Setup of the automatic tomographic measurements. Instrument architecture : 4 antennas configuration

IGARSS 2011 VANCOUVER – Tuesday, July 26 – TU4.T05 SAR/Lidar Sensing TropiSCAT first results Extremely high coherence on tower Range gate on the tower at P band :  Validation of coherence measurements

IGARSS 2011 VANCOUVER – Tuesday, July 26 – TU4.T05 SAR/Lidar Sensing TropiSCAT first results Diurnal cycle & High coherence for one day interval Strong decorrelation during storm, stronger for foliage only Strong decorrelation night/day Stronger decorrelation for full forest  High influence of soil  Prominent influence of soil moisture variation ? Further analysis necessary with ground data Range gate on the forest at P Band : 24 hours

IGARSS 2011 VANCOUVER – Tuesday, July 26 – TU4.T05 SAR/Lidar Sensing TropiSCAT first results Foliage only at 2 bands : Stronger decorrelation at L band Stronger decorrelation on HH at L band P band L band

IGARSS 2011 VANCOUVER – Tuesday, July 26 – TU4.T05 SAR/Lidar Sensing TropiSCAT first results Full forest at 2 bands : For HV : day night same order of decorrelation. Stronger decorrelation on VV at L band during the whole day, including same hour. Stronger decorrelation at L band for HH. P band L band

IGARSS 2011 VANCOUVER – Tuesday, July 26 – TU4.T05 SAR/Lidar Sensing TropiSCAT development Project evolution/planning : October 2010 – Preliminary campaign with light equipment. June 2011 – Setup of the automatic full-polarimetric backscattering and coherence measurements. September Setup of the automatic tomographic measurements. Instrument architecture : Antenna array configuration : 20 antennas

IGARSS 2011 VANCOUVER – Tuesday, July 26 – TU4.T05 SAR/Lidar Sensing The preliminary experiment has demonstrated the feasibility of the concept The TropiSCAT experiment has been partially installed in French Guiana and is currently running The first measurements show that TropiSCAT experiment can achieve the scientific objectives The first results yield physical interpretation 19 Conclusion

IGARSS 2011 VANCOUVER – Tuesday, July 26 – TU4.T05 SAR/Lidar Sensing 20 TropiSCAT : A MULTI-FREQUENCY POLINSAR DATA CAMPAIGN OF ACQUISITION FOR VEGETATION CHARACTERIZATION Thank you for your attention. (360° panorama from the top of the tower)

IGARSS 2011 VANCOUVER – Tuesday, July 26 – TU4.T05 SAR/Lidar Sensing 21 4 antennas configuration Project evolution/planning : October 2010 – Preliminary campaign with light equipment. June 2011 – Setup of the automatic full-polarimetric backscattering and coherence measurements. September Setup of the automatic tomographic measurements. Antennas configuration : 85cm 70cm 150cm T-V T-H R-H R-V Tower Forest

IGARSS 2011 VANCOUVER – Tuesday, July 26 – TU4.T05 SAR/Lidar Sensing 22 Modeling Comparisons between measurements and modeling :  Interpret the temporal variations observed in the long term experiment. Situation of the plot : West side of tower Surface of 172 m²

IGARSS 2011 VANCOUVER – Tuesday, July 26 – TU4.T05 SAR/Lidar Sensing 23 Modeling Comparisons between measurements and modeling :  Comparisons with measurements from the TropiSAR airborne campaign

IGARSS 2011 VANCOUVER – Tuesday, July 26 – TU4.T05 SAR/Lidar Sensing Deforestation Regeneration 24 Introduction and Context Carbon fluxes and its uncertainties [BIOMASS 08]  Biomass changes on tropical forests  P-band (435MHz) now available Carbon Budget