A method and apparatus are provided for automatically generating a terrain model for display during a simulated flight along a predefined mission route. The apparatus includes a mission profiler that automatically determines the area containing the mission route for which the terrain source data is required and the respective resolution of different regions within the area. The apparatus also includes an apparatus for automatically collecting the terrain source data including a search engine for automatically searching electronic collections of terrain source data to identify terrain source data covering the area containing the mission route. The apparatus also includes an image engine for processing the terrain source data into one or more predefined formats and a terrain engine for automatically compiling the processed data to create a terrain model for display during flight simulation.