A GPS based navigation aid for the blind

In this paper we present development of the GPS based navigation aid for blind. That aid utilizes inverse DGPS positioning module which, along with other benefits for the blind user, enables implementation of more complex navigation algorithms. In particular, we have implemented DGPS algorithm augmented by altitude data available from digital map. This solution improved the availability of positioning by more that 23% and its accuracy by more than 15%. All the results were experimentally verified.