Forest Height Inversion by Combining S-RVOG Model with Terrain Factor and PD Coherence Optimization

The widely used random volume over ground (RVOG) model in forest height inversion with polarimetric SAR interferometric (PolInSAR) technology do not consider the effect of terrain slope. Besides, the classical and widely applied three-stage inversion method is affected by the errors about estimation of underlying topography phase and pure volume coherence. In order to correct these two types of errors, a forest height inversion strategy is proposed. On the one hand, a slope RVOG (S-RVOG) model is adopted in this paper which incorporates the range terrain slope factor to correct the terrain distortion; on the other hand, the phase diversity (PD) coherence optimization is introduced to improve accuracy of underlying topography phase estimation in line fit process and pure volume coherence estimation. In order to verify efficiency of the method, a simulation experiment is carried out by using PolInSAR data in different range slope levels simulated by PolSARpro software provided by ESA. Then, E-SAR airborne full polarization data provided by DLR are utilized to test real scenario. Finally, it is conducted that some qualitative and quantitative analyses. The results show that for the different data in different range slope levels, the inversion method promises to correct effect due to terrain distortion in RVOG model and compensate error effect in traditional three-stage inversion method. Therefore, the proposed method provides much more accurate estimation of forest parameters