Very interesting link... From 5.4.3, it actually looks like their magnetic positioning system works better in an indoor environment with lots of magnetic pertur

Very interesting link... From 5.4.3, it actually looks like their magnetic positioning system works better in an indoor environment with lots of magnetic perturbations. I would not have expected that result, but thinking about it more it does make sense. They are estimating "where have I moved" using the local magnetic field, which is very different than how GPS works "where am I in relation to a fixed constellation".