This is a Postdoctoral Researchers Project funded by the Academy of Finland. The objectives of this project are to develop new, rigorous methods for the production of geometrically accurate, multi-spectral, multi-angular, reflectance time series from airborne images and to investigate their exploitation in various applications. The processing requires geometric and radiometric calibration of the imaging system and the rigorous geometric and radiometric modeling of the imaging process and the object. The measurement, modeling, quality, and utilization of the bidirectional reflectance factors (BRFs), based on airborne imagery, will be emphasized.