Prediction about how migrants move in the preborder terrain is important for effective border control. In this paper we present a method to obtain permeability indicators for accessibility and concealment on the basis of geographical terrain features, derived from high resolution satellite data. The indicators are used to estimate the mobility of migrants. A model to predict the density of migrants arriving at the border, and to assess the impact of security measures, is introduced and discussed. The model was implemented and tested. The results are used as value adding products in pre-operational services for border control. Validation has to be done using actual irregularborder- crossing geo-oriented statistics. By the time this paper was written no such statistics were available.