Any estimation algorithms that allow a user to indicate that certain Solutions are impossible? Variations of the Kalman filter and other algorithms are used for navigation and target tracking. Often times certain solutions might as well be deemed impossible based on known topography in the area. Without accounting for the topography, the algorithms I know of might say that a submarine is most likely under the sea floor, or that an aircraft has tunneled into a mountain. Preferably, an algorithm would give the most likely solution after treating certain solutions as impossible. 


Are there any estimation algorithms that do this sort of thing? 
If there are such algorithms, what are they?
This series of papers tries to enforce such constraints.

The constraints are on the state of the Kalman filter: