The Extended Kalman Filter with profile matching

has been employed to extract road maps in satellite images.

This algorithm suffers from several drawbacks

that result in its poor performance in difficult situations.

To improve its performance in those situations,

like junctions and varying road characteristics, we propose

to use the Unscented Kalman Filter which can deal

better with the nonlinearity of the road model. Additionally,

we use an approach to dissociate the system

measurements from the current state prediction of the

Kalman filter. This method removes the potential for

the instability of the algorithm.