Position determination method for vehicle mounted navigation system, involves correlating determined position with known area when shadowing radio signals by obstruction is detected

摘要

The method involves correlating determined position with known area when shadowing of at least one of the radio signals (s1-sn) by obstruction such as bridge (2), is detected. Preferably, the position of the bridge is stored in a digital map. An Independent claim is also included for position determination device.