> What we need, and will probably get soon, is inertial guidance based on laser ring or fibre optic gyros in mobiles. You get a location fix every week or so and it starts out much more accurate than gps.
Corrections every week? This isn't possible given the drift rates of high end FOG or Lazer ring IMUs. A high-end marine-grade INS can cost over 1 million dollars. These systems will typically provide un-aided navigation solution drifts that are less than 1.8 km per day. This means that if the device were left stationary for one day, due to slight errors in the sensors and imperfect sensor calibrations, after integrating the position solution, the calculated position after one day would be 1800 meters away from the sensors actual position.
With ones that you can affordably put in a phone within minutes the drift will be huge. You need something to regularly correct for the drift and currently this is GPS.
Corrections every week? This isn't possible given the drift rates of high end FOG or Lazer ring IMUs. A high-end marine-grade INS can cost over 1 million dollars. These systems will typically provide un-aided navigation solution drifts that are less than 1.8 km per day. This means that if the device were left stationary for one day, due to slight errors in the sensors and imperfect sensor calibrations, after integrating the position solution, the calculated position after one day would be 1800 meters away from the sensors actual position.
With ones that you can affordably put in a phone within minutes the drift will be huge. You need something to regularly correct for the drift and currently this is GPS.