Forest biomass and biomass change with spaceborne SAR

Forskningsprojekt, 2017 – 2018

The objective of the research project is to investigate X-, C-, L-, and P-band SAR data from the satellites TanDEM-X, Sentinel-1, ALOS PALSAR, ALOS-2 PALSAR-2, together with airborne SAR and tower-based radar data for forest biomass and tree height estimations and their change with time, both in boreal and hemi-boreal forests. The change studies include detection and mapping of clear-cuts, thinnings, wind-thrown damages and growth. The research will focus on investigating advanced SAR techniques, i.e. polarimetry, interferometry and tomography. Time series data will be investigated to improve biomass and biomass change estimates. Future satellite SAR mission concepts based on passive companions to SAOCOM and Sentinel-1 with interferometric and tomographic capability will also be investigated. The methodology is, as a first step, based on evaluating concepts and algorithms at plot level (radius ≥ 10 m) relating the forest variables estimated from field data to SAR data at two different test sites in Sweden. In a second step, error assessment will be performed at stand level and by comparison with airborne laser scanning data. Finally, a regional up-scaling will be performed to cover large parts of two counties in Sweden. At one of the test sites, a 50-m high tower equipped with a polarimetric, interferometric and tomographic radar will be used to collect time series data and investigate the temporal radar signatures in order to understand, model and mitigate the effect of environmental conditions (wind, temperature etc). The programme includes the funding for two Ph.D. students at Chalmers and one at SLU.