ASSESSMENT OF INSAR TREE MAPPING ACCURACY IN TROPICAL RAIN FORESTS

摘要

Well-characterised reference sites are of major importance for accuracy assessment and validation of tree mapping algorithm, which is derived from single track InSAR C-, X-band Dornier system acquired during the ESA-MOF INDREX-96. A challenging study area was chosen in a 7.2 ha FIEPLP (Forest Inventory & End Product Linking Program) plot area in East-Kalimantan Indonesia. All trees of this site are described by position, geometrical dimensions and species name. Since no ground control points such as corner reflectors were used for this research, the validation of the results is realised by using visual reference points. As a first step the crown projections terrestrially measured, then the InSAR crown projection map was derived to verify their planimetric accuracy and to make a first evaluation of the vegetation cover as observed by InSAR. To match trees identified by the InSAR with trees measured terrestrially, an algorithm was designed to evaluate the 3D positions and crown dimensions of all trees measured in the field with InSAR derived tree 3D positions and crown dimensions. The resulting table for candidate matches contains the distance data that can give the information for assessing the positional accuracy and tree crown size projection. This study report how is modelling can be implemented for forestry in Indonesia and shows possible ways for the improvement of tree parameter estimation.