Forest Height Estimation Method Using TanDEM-X Interferometric Coherence Data

【Objective 】 Using single polarization TanDEM-X InSAR data,we studied the forest height estimation method with InSAR coherence amplitude,and analyzed the effects of different DEMs spatial resolutions(one is LiDAR DEM of 5 m resolution and the other is SRTM DEM of 30 m resolution) on forest height estimation accuracy. 【Method】First,non-volumetric decorrelation was corrected from the observed coherence in order to obtain the volumetric decorrelation(γVol),and then based on the SINC model,the amplitude of γVolwas used to estimate forest height.Then forest height inversion results were validated against LiDAR CHM data and compared with the method based on phase difference.Plot sizes of 15 m × 15 m,30 m × 30 m,50 m ×50 m and 100 m × 100 m were selected to analyze the effects of spatial interpolation. 【Result】 The effects of DEMs in two kinds of resolutions(5 m×5 m,30 m×30 m) on inversion accuracy are small,when plot size is 100 m×100 m,the R~2 are 0.54 and 0.51,the RMSEs are 2.38 m and 2.51 m,and the overall accur