Device helps navigate daily life
Satellite-based navigation gadgets can guide motorists from high above, saving bumbling drivers countless hours and extra trips to the gas station. But directing people on a much smaller scale -- such as inside an office -- is a much greater challenge.
Locator equipment based on Global Positioning System satellites is accurate to about 10 feet -- fine for drivers searching for the next right turn but not for pedestrians seeking a front door. And the range of GPS is limited indoors, and it can't on its own differentiate between a path and a wall.
