Global Positioning System technology (GPS) is a great invention, able to map your movements and save you from getting lost in strange city streets - until you go into a tunnel, between tall buildings or hit any other barrier that might block the satellite signal your device relies on.

Spatial information systems researchers at UNSW are working to end GPS dropouts by combining satellite-reliant GPS with a non-satellite-based technology called Inertial Navigation System (INS).

The goal is to create an affordable positioning system which works accurately and seamlessly indoors and out.

So far effective GPS/INS systems have been built by major defence and technology companies but the enormous cost of these high-tech systems puts them well out of the reach of consumers.

Now the work of Dr Yong Li and colleagues in UNSW Engineering's Satellite Navigation and Positioning Lab (SNAPlab) could be the breakthrough that makes seamless GPS/INS navigation available for everyday use.

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