An efficient strategy for the inversion of bidirectional reflectance models with satellite remote sensing data

The angular distribution of radiation scattered by the earth surface contains information on the structural and optical properties of the surface. Potentially, this information may be retrieved through the inversion of surface bidirectional reflectance distribution function (BRDF) models. This thesis details the limitations and efficient application of BRDF model inversions using data from ground- and satellite-based sensors.; A turbid medium BRDF model, based on the discrete ordinates solution to the transport equation, was used to quantify the sensitivity of top-of-canopy reflectance to vegetation and soil parameters. Results were used to define parameter sets for inversions. Using synthetic reflectance values, the invertibility of the model was investigated for different optimization algorithms, surface and sampling conditions. Accurate solutions were obtained in all cases except for an overhead sun, an optically-thick canopy and sampling geometries exclusively in the orthogonal plane. Surface state parameters (e.g., spectral albedo, absorbed radiation) were retrieved more reliably than model parameters.; Inversions were also conducted with field data from a ground-based radiometer. First, a soil BRDF model was inverted for different soil and sampling conditions. A condition-invariant solution was determined and used as the lower boundary condition in canopy model inversions. Canopy parameters were retrieved accurately when reflectance was sampled under preferred conditions (spectral and angular). Estimates of shortwave albedo and surface absorbed radiation were accurate; estimates of canopy absorbed radiation exceeded measured values.; Finally, a scheme was developed to improve the speed and accuracy of inversions. The scheme weights empirical data with the partial derivative of angular reflectance with respect to a model parameter. Inversions with data from the satellite-based Advanced Very High Resolution Radiometer (AVHRR) were conducted with this scheme. The inversions accurately retrieved leaf area index and leaf optical properties.; This research relied extensively on data from the First International Satellite Land Surface Climatology Project (ISLSCP) Field Experiment (FIFE). This experiment was conducted on grasslands near Manhattan, Kansas. Results can provide a foundation for inversions of BRDF models on a larger scale.