Apparatus for detecting location of mobile body in navigation system and method thereof

A method and an apparatus for detecting location of a movable body in a navigation system comprising a map data detector for detecting map information of a region corresponding to location information from an external digital map storage based on location information of the movable body transmitted from sensors sensing the location and traveling information of the movable body; a memory for storing the map information; a filter for computing an optimum location of the movable body including road error; and a map-matching unit for receiving the optimum location information of the movable body and correcting the optimum location information and the map information stored in the memory. The method and apparatus can apply a constraint to the location of the movable body by computing the location of the movable body including a width of road, in comparison with a case using only direction of road as a measured value.