1. An improved accuracy sensory system for vehicle navigation comprising: first means for sensing a navigation parameter of a vehicle and for providing a first signal indicative of said navigation parameter; second means for sensing said navigation parameter of the vehicle and for providing a second signal indicative of said navigation parameter; means for classifying a difference between said first signal and said second signal into a plurality of sets representative of predetermined behaviors; and means for providing a clearness coefficient for the first signal dependent on a degree of participation of the difference between the first and second signals in each of the plurality of sets.