IGARSS-2011-Vancouver Temporal decorrelation analysis at P-band over tropical forest Sandrine Daniel, Pascale Dubois-Fernandez, Aurélien Arnaubec, Sébastien Angelliaume IGARSS 2011, Vancouver

IGARSS-2011-Vancouver Overview TropiSAR Campaign Temporal coherence Methodology Paracou Analysis Tomography Conclusion

IGARSS-2011-Vancouver Translating objectives into flight scenario TropiSAR objectives Evaluate the BIOMASS mission concept over tropical forests Provide a dataset for algorithm validation Radiometric analysis Reference plots with range of biomass in the high values Up to 520 t/ha Temporal decorrelation analysis Identical trajectories flown on different dates (22 days) PolInSAR Vertically shifted trajectories (100ft and 50ft) Adequate altitude of ambiguity throughout the swath Tomography Six vertically shifted trajectories 0 ft, 50ft, 100ft, 150ft, 200ft, 250ft

IGARSS-2011-Vancouver TropiSAR: the campaign the in-situ database CIRAD-EDB - based on permanent plots managed by Guyafor project - 28 plots – 157 ha measured trees, diameter > 10cm - biomass ranging from 100t/ha to 500t + /ha the SAR database ONERA - 7 flights over 22 days the data analysis - CESBIO: radiometry – polarimetry - ONERA: PolInSAR - IRD: Polarimetry - EDB-CIRAD: in-situ error +….. Under fundings from ESA, CNES and ONERA

IGARSS-2011-Vancouver TropiSAR: the sites Paracou Arbocel Nouragues Rochambeau Kaw

IGARSS-2011-Vancouver TropiSAR: the waveform ParameterP-BandL-Band Geometry Altitude [ft,m]13000/ 3962 Velocity [m/s]120 Waveform ModeFull-Polar Peak Power [W] Actual PRF [kHz]2.55 Sampling rate [MHz]500 Bandwith [MHz] Processed wave length [m] – Processed Bandwidth [MHz] (B=125 MHz) (B=150 MHz) Relative bandwidth [%] 3111 Range Resolution [m] Azimut resolution [m] Range pixel spacing [m] Azimuth pixel spacing [m] Near Range [m]4350 Nb of pixels in range Incidence angle range [°]

IGARSS-2011-Vancouver Acquisition geometry

IGARSS-2011-Vancouver TropiSAR: August 2009 TropiSAR DescriptionDate Vol 0Validation/calibration10-August Vol 1Standard12-August Vol 2Tomography Nouragues14-August Vol 3Standard17-August Vol 4Tomography Paracou24-August Vol 5Standard30-August Vol 6Standard01-Sept Temporal decorrelation analysis - PolInSAR Tomography - PolInSAR 22 days

IGARSS-2011-Vancouver Database over Paracou Temporal Shift Vertical Shift Flight 0 Flight 1 Flight 2 Flight 3 Flight 4 Flight 5 Flight 6

IGARSS-2011-Vancouver TropiSAR: the temporal decorrelation kz

IGARSS-2011-Vancouver Interferometric coherence wrt temporal baseline 2 days 14 days 4 days 7 days 20 days 22 days Presented at PolInSAR-2011 Objective: complete the temporal analysis with all possible combinations

IGARSS-2011-Vancouver Available temporal baselines over Paracou

IGARSS-2011-Vancouver Systematic methodology InSAR Coherence Temporal Coherence Noise decorrelation Temporal decorrelation Scattering decorrelation ? RVoG model Spectral shift Negligible in airborne context

IGARSS-2011-Vancouver Systematic methodology InSAR Coherence Temporal Coherence Noise decorrelation Temporal decorrelation Scattering decorrelation ? Spectral shift Negligible in airborne context

IGARSS-2011-Vancouver Temporal Coherence: Paracou Correct for SNR contribution Compute coherence histogram over Rois f Compute histogram peak for  min >0.95 RGB Hh-Hv-Vv

IGARSS-2011-Vancouver Paracou Analysis Temporal Coherence: Paracou RGB Hh-Hv-Vv  SNR <0.99

IGARSS-2011-Vancouver Ground elevation estimation under dense forest using P-band T-SAR LIDARP-Band, Hh Hv Vv T-SAR : P-Hh, N=6, 21x21 -40m 5m RMSE = 4.4 m

IGARSS-2011-Vancouver Conclusions Temporal coherence analysis over tropical forests at P-Band Systematic analysis was performed to explore if a decreasing trend was visible The imperfect trajectories created artefacts in the analysis A criteria based on the RVoG model was proposed to select areas with proper kz No clear trend was observed and the temporal coherence remains high even for the longest temporal baselines Ground elevation estimation under dense forest using P-band T-SAR

IGARSS-2011-Vancouver Questions?!? Temporal decorrelation analysis at P-band over tropical forest IGARSS 2011, Vancouver