Radarkartering av skogsbiomassa med P-band Pol-InSAR Lars Ulander, Maciej Soja, Gustaf Sandberg, och Daniel Murdin
Contents BIOMASS ESA candidate mission P-band satellite SAR Level-2 algorithm development Airborne SAR experiments Biomass retrieval evaluation
3 ESA:s Earth Explorers ESA has six Earth Explorers launched or under development in the Living Earth Program Launched: GOCE, SMOS, Cryosat-2 Under development: ADM-Aeolus, Swarm, Earthcare 7th Earth Explorer Launched currently planned for 2016 Three candidates in phase A: BIOMASS, CoreH20, Premiere Final mission selection with be in 2012
BIOMASS: First P-band SAR in space Courtesy: ThalesAlenia Space Synthetic aperture radar MHz ( = 0.7 m) Large deployable reflector antenna (diameter = 12 m)
BIOMASS: Challenges & solutions Large deployable antenna Heritage from communication antennas (e.g. Inmarsat-4) Ionospheric corrections Faraday rotation corrected by polarimetric analysis Algorithms for global biomass mapping Polarimetry and repeat-pass interferometry (main orbital phase) Multiple baselines, i.e. tomography (initial orbital phase)
Airborne P-band SAR experiments Objectives Temporal stability (correlation) Topography and moisture effects PolInSAR, tomography, P/L-band BioSAR (2007, 2008, 2010), Sweden Boreal forest at Remningstorp, and Krycklan TropiSAR (2009), French Guiana Tropical rain forest at Paracou and Nourages Remningstorp Krycklan French Guiana Paracou Nourages Sweden
BioSAR-1, 2007: Remningstorp Hemi-boreal forest in southern Sweden Stand-level biomass tons/ha; Managed forest Topographic height variations are small ( m)
Radar backscatter coefficient vs Biomass Blue crosses: 58 training stands Red circles: 10 validation stands HVHHVV SAR data from one date (2 May); similar for other dates Correlation with biomass is high for HV & HH but low for VV
BioSAR 2007: Height maps Low-altitude high-resolution helicopter scanning lidar 0.25 m grid Height (m) Airborne P-band repeat-pass PolInSAR 2 m resolution
BioSAR 2007: Biomass maps Low-altitude high-resolution helicopter scanning lidar 0.25 m grid Airborne P-band HV- polarisation 2 m resolution Biomass [tons/ha]
Biomass retrieval error 2 May, heading 200 deg Retrieval based on HV-polarisation Stable results for all dates 9 Mar2 April2 May RMSE validation 32 t/h35 t/h42 t/h RMSE cross- validation 33 t/h34 t/h
Conclusions Phase-A for 7th Earth Explorer candidates ends 2011 BIOMASS mission concept matured Large deployable antenna Faraday rotation corrections Biomass retrieval algorithm Level-2 biomass algorithm needs further development Current estimates indicate RMSE = t/ha ( t/ha) Topography and moisture corrections Combination estimates BIOMASS end-to-end-simulator