Trilateration is like triangulation, but uses the distances to landmarks, rather than their angles, to determine one’s location. GPS is probably the most common example of trilateration in use at the moment.
In our problem we have a set of landmarks. We know the distance (with some uncertainty) to one, and we want to know which of the remaining landmarks we should select next to maximise the amount of information we gain about our location.
For our particular example, we ask people to estimate the distance of various landmarks from their house.
We look at how to find a good landmark quickly, by using Bayes’ rule to rearrange the expression for the entropy in the probability distribution.