When GPS positioning is unavailable (or even when it is available sometimes), Google Maps for mobile shows a blue circle of uncertainty around the blue self-localization dot. What exactly (statistically) does this blue circle represent?
Is it the 95% confidence interval? Since it does change in size, I am assuming it is some representation of accuracy. Is it just a rough guideline or are there are some actual numbers going in to an accuracy calculation which is then represented visually?
