this code predicts the satellite signal from 0.25 to 4.0 microns assuming cloudless atmosphere.the main atmospheric effects (gaseous absorption by water vapor,carbon dioxyde,oxygen and ozone; cattering by molecules and aerosols) are taken into account. non-uniform surfaces may be considered,as well as bidirectional reflectances as boundary conditions . the following input parameters are needed geometrical conditions,atmospheric model for gaseous components, aerosol model (type and concentration), spectral condition , ground reflectance (type and spectral var.), at each step, you can either select some proposed standard conditions (for example,spectral bands of satellite for spectral conditions) or define your own conditions(in the example,you have to define the assumed spectral response).