Forest biomass retrieval from BioSAR 2010 P-band SAR data using a regression-based model

A model for retrieval of boreal forest biomass from polarimetric P-band SAR images developed using the BioSAR 2007 and BioSAR 2008 data sets is revisited and evaluated using data from BioSAR 2010. Incorporating the HV backscatter component as well as the HH/VV ratio and the ground slope, the model is noteworthy as performing well when retrieving biomass values in Remningstorp using parameters trained in Krycklan. These two Swedish test sites are separated by 720 km and represent two different types of boreal forest as well varying topography. SAR images and biomass estimates obtained from Remningstorp in 2010 provides an opportunity to test the model further. This dataset results in a qualitative reproduction of the previous result, showing the expected changes due to forest management, but with a relative overestimation of biomass. A large part of this can be explained by the timing as the new acquisitions took place during early autumn instead of spring with the associated changes in moisture conditions.