Chosen Solution
Have you ever encountered smart-phone types where you could disconnect the modem independently of GPS? I know that it’s easy to disconnect the antenna. This works on all hardware I’ve seen. Unfortunately, this also disables GPS if I’m not mistaken. Hence, my question if you know of any smart-phones (PURISM aside) where you can unplug the modem and still have a working smart-phone with GPS, in forced airplane-mode (disabled hardware).
Cell phones & tablets which have cellular modems use two methods of triangulation for location. GPS and GLONASS which are space based. Both can encounter issues within dense cities, these systems are augmented with cellular tower positioning. So as you can see the need of the cellular is still needed to get positioning. I don’t know of any way to disable the cellular services without effecting the effectiveness of the positioning. Maybe we need to look at this from the other direction… Do you need to have an active contract with a carrier to still use GPS with cellular positioning? I can tell you a iPad with LTE services does not need to have a carrier contract and still have GPS working.
