The perspectives of expansion in air traffic volume for the next years create important challenges in monitoring and control fields. In this scenario a new concept named ADS-B is rising based on cooperative aircrafts to provide air traffic control. The technique has been disseminated by regulatory agencies of all over the world and its popularity is increasing. It seeks for integration with the actual radar based sensors to provide information with better accuracy to traffic monitoring using parameters supplied by airborne position and navigation systems based on satellite communication. The present work evaluates the efficient use of both sensors data - radar and ADS-B - through the use of data fusion techniques. Centralized and distributed fusion are evaluated showing improvements in aircraft track estimation in both cases, when information from a simulated GPS system is used. The conclusions point to the fact that the system is able to accommodate the expected traffic growth with reduction in aircraft separation rules with greater predictability of its movement.