[mateo1]

I would like to add something to this. My Android phone refuses to use the GPS only navigation with the default Google Maps app. Even when AGPS is enabled and possible, the almanac downloaded beyond reasonable doubt and my last location known down to a meter. That's just google doing their thing.

Expanding, most navigation apps in the name of preserving "user experience" will actively hide when they fail to work. They won't mention that signal is lost and instead they'll dead recon you within the confines of the road or path you were last in. GMaps will go a step further and simply guess where you just turned at a junction... which is extremely confusing when wrong and the main reason I'm no longer using Gmaps for my car.

I guess what I'm trying to say is this: do not, under any circumstances, mistake your consumer smartphone with stock navigation apps as a reliable navigation device. Especially when getting lost might cost you your life.