A new chip technology has been developed by u-blox, called 3D Dead Reckoning (ADR), that can track you even when GPS and signal are lost.
The chip is aimed at cars initially to help improve navigation. Using smart 3D algorithm tracking the chip is able to locate a user accurately to within 2 metres, even when under the cover of a parking garage or tunnel.
The 3D ADR chip uses gyroscopic and accelerometer data, as well as wheel movements, to track its location. This means it can even detect a car's angle on an incline or decline. This is ideal when changing between levels in a parking garage.
The idea is that the 3D ADR chip steps in when GPS or GLONASS connectivity fail, effectively filling in the blanks. From a consumer perspective this will mean a consistently accurate navigation system, no matter the car's location. It should also help police to track stolen cars more effectively.
We contacted u-blox and it sounds like there are no plans to make a mobile version for phones or tablets, but the technology is there for anyone willing to put the work into development.