Different atmospheric models to calculate the wind field near the surface in complex, hilly terrain shall be connected and extended to allow the simulation of the flow field ranging from the meso-beta to the micro-alpha scale. The results of simulations must be checked against observations. This is very important for wind energy calculations and dispersion of pollutants where there is a need to estimate the local wind power or pollutant concentration. These local values are affected by atmospheric processes on all scales. At the same time the possible application to many different places or real-time applications require that the calculation should be very efficient.