A method to estimate tree trunk diameter and its application to discriminate Java-Indonesian tropical forest characteristics

This paper discusses a numerical method to analyse interaction of L-band microwave on tree trunk using mode expansion method. The authors investigated backscattering coefficient of teak (Tectona grandis), pine (Pinus merkusii), mahagony (Swietenia macrophylla), and rasamala (Altingia excelsa). This method approximates tree trunk as an infinite length of three layers cylindrical dielectric mediums. Horizontal polarisation of scattered wave is derived to calculate relationship of tree trunk diameter and its backscattering coefficient. The validation of these analysis results are investigated by wave scattering simulation using finite difference time domain (FDTD) method, and both have good agreement in results. These results are applied to discriminate tree trunk diameter from JERS-1 SAR image. The authors choose study area at Cisarua tropical forest area, part of Mount Gede Pangrango National Park, West Java, Indonesia. Finally, these results are compared with field survey data of study area