Development of Forest Height Estimation Using InSAR/PolInSAR Technology

Forest height estimation is one of the hottest research areas of InSAR/PolInSAR technology within its 30 years’ development.Estimation algorithms play an important role in the forest height assessment by InSAR/PolInSAR technologies.This paper systematically reviewed the basic theories，model assumptions and then summarized the limitation and potential of these algorithms applied in forest height estimation，especially performed in regional or global scale.It also deliberated the intrinsic characteristics of these algorithms like DEM difference method，three\|stage inversion process，coherence amplitude method and so on.Analysis showed that the estimation results of DEM difference method had higher accuracy and less influence from forest types and structure.So it had great potential for global and regional forest height assessment，however，it was limited by the requirement of high accuracy DEM data in those area.The result accuracy of algorithms based on PolInSAR depended more on forest types，structures and also the robust of forest scattering models.It had no restriction of DEM and could perform in global and regional scale，but for the forest area with great heterogeneous，model and algorithm suitability and robust need to further studying.Besides，for the poor penetration of single\|baseline InSAR/PolInSAR，we should focus more on multi\|dimension，multi\|baseline technique for InSAR/PolInSAR application development in the future.