Three Problems in Forest Height Inversion Using P-Band Repeat-Pass Polinsar Data

P-band PolInSAR is potential to map forest height and biomass at the global scale with the upcoming BIOMASS mission. However, there are three major problems in forest height inversion using P-band repeat-pass PolInSAR data, i.e. volume temporal decorrelation, residual ground scattering, and ground temporal decorrelation. Based on the random volume over ground (RVoG) model and the Sum of Kronecker Products (SKP) decomposition, this study developed a multi-baseline forest height inversion method to remove the joint influence of these three problems. Based on the TropiSAR 2009 datasets in Nouragues, results show that the concurrence of the three problems brought severe overestimation to three-stage inversion (RMSE of 7.6-18.8 m for different baselines). Stepwise comparisons show that each compensation of the three problems improved the inversion accuracy. The proposed multi-baseline inversion simultaneously removed all three problems and produced the best accuracy for both short ( 20 m) forest (RMSE 3.4 m), which is much better than the inversion accuracy of the used single baselines.