Estimation of leaf area index (LAI) using POLInSAR: Preliminary research

Polarimetric interferometric synthetic aperture radar (POLInSAR) has been used to extract the forest height successfully. Leaf area index (LAI) is an important parameter for the estimation of forest biomass, however presently the most of LAI extraction approaches are based on optical data. For the dense forest, the optical image is mainly the reflection of the canopy surface, and it is saturated easily for the LAI retrieval. Microwave has the relative long wave length, can penetrate into the forest and even get the backscatter information of the ground surface, so it should be an ideal tool to estimate LAI. This paper built the linear relationship between the LAI and the product of tree height and extinction coefficient, the latter two parameters can be inversed by the means of POLInSAR technique. At last, this study provides a preliminary experimental result, which shows that the linear relationship between the LAI retrieved from the SPOT-5 image and the product of tree height and extinction coefficient inversed from POLInSAR based on RADARSAT-2 image pairs.