Retrieval of Forest Biomass from ALOS PALSAR Data Using a Lookup Table Method

Wenjian Ni, Department of geography, university of maryland, wenjian@umd.edu (Presenter)
Guoqing Sun, NASA GSFC/UMD, guoqing.sun@nasa.gov

The feasibility and problems of forest biomass estimations based on lookup table (LUT) methods using ALOS PALSAR data were investigated in this study. By use of the forest structures from a forest growth model as inputs to a three dimensional radar backscattering model, a lookup table was built. Two types of searching methods (Nearest Distance (ND) and Distance Threshold (DT)) were used to find solutions from lookup table. When a simulated dataset was used to test the lookup table, the RMSE of biomass estimation were 39.133 Mg/ha (R2=0.748) from ND and 26.699 Mg/ha (R2=0.886) from DT using dual-polarization data for forest with medium rough soil surface. All results showed that DT was superior to ND. Comparisons of biomass from forest inventory data with that inversed from look up table using DT method over eight forest farms showed RMSE of 18.564 Mg/ha and 15.392 Mg/ha from PALSAR data with and without correction of the scattering mechanism, respectively. The results showed that the method has the ability to consider the influence of terrain on scattering mechanism and that the PALSAR data without terrain-correction of scattering mechanism could be directly used for biomass estimation using the lookup table method.

Presentation Type:  Poster

Session:  Other   (Tue 11:30 AM)

Associated Project(s): 

• Sun, Guoqing: Model Inversion of Multiple-Sensor Data for Forest Biophysical Parameters Retrieval ...details

Poster Location ID: 265