1. A method for adapting a radio network model to conditions of a real radio network comprising the steps of: defining different measuring positions; carrying out measurements of variables at said different measuring positions by means of a measuring arrangement adapted for generation of position dependent measured data of the radio network, thereby generating measured data; providing position-dependent modelling values by a data base adapted for storing at least the radio network model, using said measured data for said modelling values from the real radio network obtained at said measuring positions; setting by means of a data processing arrangement adapted to modify each modelling a fine grid in a radio cell, so as to define a plurality of small fine grid area portions, wherein at least one said modelling value is attributed to each area portion by said radio network model; setting with said data processing arrangement a rough grid superimposed on said fine grid thereby defining rough grid regions, each said rough grid region comprises a plurality of said fine grid area portions; obtaining measured data at said measuring positions with said measuring arrangement; and modifying with said data processing arrangement said modelling values attributed to said fine grid area portions in said different rough grid regions by a mathematical operation comprising an interpolation, which is directly dependent on said measured data of said respective rough grid area portions and said position of said fine grid area portions; wherein said mathematical operation further comprises: summarising said measured values at said measuring positions of one of said respective areas of said rough grid to one value representing said general value of said measured values; setting a reference point within said area of said rough grid to which said value representing said measured values is attributed; setting an influence radius around said reference point; and varying said modelling values in all area portions within the influence radius according to a decreasing function of the distance of the respective area portion to said reference point.