Analysis of multi-date MISR measurements for forest and woodland communities, Queensland, Australia

Many theoretical and applied studies have demonstrated that the anisotropic reflectance of the land surface is determined by the structural and optical properties of the land surface. The Multi-angle Imaging SpectroRadiometer (MISR) measures the anisotropic reflectance of the land surface thus has the potential to improve the operational mapping of canopy attributes in Queensland, one of the largest states in Australia. The aim of this study was to assess the relationship between foliage projective cover (FPC) and the shape of the bidirectional reflectance distribution function (BRDF) for a mixed grassland/woodland ecosystem, the Southern Brigalow Belt Biogeographic Region. A practical approach for deriving the surface bidirectional reflectance factor (BRF) from MISR “Local" mode data using existing MISR products is presented. The BRDF typology of the land surface was determined using shape parameters derived from inversion of the linear Ross–Thick Li–Sparse Reciprocal and the non-linear Rahman–Pinty–Verstraete (RPV) models against a time series of MISR “Local" mode surface BRF data. Following an evaluation of the models inversion error, the RPV model was examined for correlation with FPC, a canopy attribute routinely derived from Landsat data in Queensland. Our empirical analyses showed the MISR derived RPV model parameters were qualitatively related to spatial and temporal variations in vegetation structure in Queensland and the k parameter contained information independent of FPC. These results are consistent with published findings from other regions.