Tree height retrieval methods using POLInSAR coherence optimization

This paper investigates to what extent interferometric coherence optimization in radar polarimetry improves the performance of forest height inversion method using POLInSAR measured data. Based on repeat pass E-SAR data and the corresponding ground measured forest stand heights, several available forest height inversion methods are validated and compared together with coherence optimization algorithms such as the iteration for the maximization of the magnitude difference (BF-mag) coherence optimization algorithm and phase diversity (PD) coherence optimization algorithm. The results show that coherence phase optimization can improve the performance of the tree height retrieval method based on coherence phase information, but can not improve the performance of the retrieval method based on coherence amplitude information alone. Furthermore, an integrated inversion method, which combines coherence phase with coherence amplitude information and includes corresponding polarization coherence optimization and compensation of non-volume scattering decorrelation, is proposed and discussed.