(Replying to PARENT post)
According to the paper, one nautical mile per day was state of the art in 2006. They are shooting for one mile/month now
👤monort🕑7y🔼0🗨️0
(Replying to PARENT post)
Fibre optic gyros can be miniturized to millimeter dimension, if it wasn't for ITAR.
High end civilian IMU's typically use mechanical gyros which have been obsolete for decades. Also, a phone isn't typically moving constantly like the oceans so error rates would be lower.
👤thermodynthrway🕑7y🔼0🗨️0
(Replying to PARENT post)
Plus the gyros would have to be powered at all times -- that's not gonna work on mobiles.
👤cryptonector🕑7y🔼0🗨️0
(Replying to PARENT post)
So this is why my smartwatch can tell me my speed before it has a GPS lock, including indoors? Very cool! But of course, as you say, the reports of my absolute position are very inaccurate.
👤kqr🕑7y🔼0🗨️0
(Replying to PARENT post)
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.