Bound carbon estimates from biomass measurement using multi-polarisation, multi-wavelength (AIRSAR) radar data in the North Island, New Zealand

Multi-polarisation, multi-wavelength SAR data from the 1996 NASA/JPL PACRIM mission was evaluated to determine radar suitability for mapping evergreen forest and scrub biomass in New Zealand. Biomass, species, tree height, stem number and density were measured for test sites in both indigenous vegetation and exotic plantation forest. These measurements were compared with various radar indices, including total power, scattering matrix values, and various arithmetic combinations of scattering matrix values. Results show a significant correlation between biomass and total power (exotic sites) and between biomass and scattering matrix VV:HH ratio (indigenous sites). An examination of co- and cross-polarisation plots show that exotic and indigenous vegetation can be clearly identified using P- and L-band imagery, and that these two classes can themselves be discriminated using C-band data. The results of the study show that the required targets for biomass measurement can be identified, and above-ground biomass estimated, from multi-polarimetric data.