1. A method, comprising the steps of: receiving a signal at a mobile receiver; calculating an estimation of the current position of the mobile receiver within a topological region based upon the received signal; accessing one object-based database comprising geometrical objects representing navigable routes, each geometrical object comprising a topological region identifier attribute and a geometry attribute defining the geometry of a complete representation of the navigable route; determining a probable geometrical object representing a navigable route where the mobile receiver is probably located from among geometrical objects having a region identifier attribute associated with the topological region in the one database; and comparing the estimated position of the mobile receiver to the probable geometrical object representing a navigable route and if the estimated position differs from a position coinciding with a portion of the probable geometrical object, adjusting the estimated position to a probable position coinciding with a portion of the probable geometrical object.