1. Method for generating an orthorectified tile comprising:— retrieving a sequence of source images obtained by a terrestrial based camera mounted on a moving vehicle driving across a surface of the earth; retrieving position data associated with the retrieved source images, wherein the retrieved position data includes constant position parameters defining a relationship with a reference position within the vehicle and variable parameters in a geographic coordinate reference system corresponding to a coordinate location of the vehicle's reference position in said coordinate reference system;— retrieving orientation data associated with the retrieved source images, wherein the retrieved orientation data includes constant orientation parameters having a relationship with the orientation of the camera with respect to a reference orientation of the vehicle and variable orientation parameters in the geographic coordinate reference system corresponding to the orientation of the reference orientation of the vehicle in the coordinate reference system;— converting a source image by way of corresponding position data and orientation data to obtain the orthorectified tile and corresponding metadata defining a conversion of pixel coordinates in an orthorectified image to a position in the geographic coordinate reference system.