Potential of the forest height derived by polarimetric SAR interferometry to estimate forest biomass

Abstract

Single baseline polarimetric SAR interferometry (Pol-InSAR) is sensitive to the vertical distribution of scattering mechanisms. By using the “Random Volume over Ground” model, Pol-InSAR data over forests in L-band could be inverted to forest height maps of high accuracy. Forest height itself is a useful parameter, but for most application forest biomass is the parameter of main interest. The conversion of forest height to forest biomass has two main aspects: (1) the relationship between forest height and biomass, and (2) the connection between the height retrieved by the Pol-InSAR and the height needed for the biomass conversion. This contribution focuses on the first aspect and retrieves a height-biomass relation for four common tree species of Middle Europe from forestry yield tables. It is shown that the height biomass relation can be described by an allometric equation: Biomassforest = 1.52·mid height1.52. This relation is to a large degree independent of the regarded species, conventional thinning intensities and over a large range of site conditions. The significance of height-biomass allometry is discussed under the light of different (not table-conform) forest types and the implications for the forest height that is retrieved from polarimetric interferometric SAR.