Method to speed up LUT-based crop canopy parameter mapping

Estimation of canopy biophysical and biochemical parameters using remote sensing data is important for regional crop-growth condition monitoring and yield assessment. The inversion of the radiative transfer model PROSAIL based on the look-up table (LUT) approach is widely used for this purpose, taking remotely sensed reflectance as input. For the LUT-based parameter mapping, the main part is searching for the optimal solution from a large LUT. Due to the computational complexity of the sorting algorithm and size of the LUT for the solution search, a substantial amount of time is normally needed for estimation. In order to speed up the mapping of parameters using remote sensing observations, a faster method is developed for searching the LUT by introducing a binary search algorithm. The results of the experiments based on SPOT-5 imagery show that the proposed method can increase the mapping speed by about 70 times compared to the sorting algorithm.