[stefan_]

If you had to break it down to the essential parts, how much would it weigh? Do you rely on having measured the area you are flying in previously?

[shannonclaude]

Currently 20-40 pounds right now, but we're working to reduce the SWaP. MagNav does rely on having accurate magnetic anomaly maps, which the government and certain private companies have access to.

[skywal_l]

Are those anomalies change over time? Do you have to continuously update those devices with the latest maps?

[shannonclaude]

They change over geological timescales—so not anytime soon. We're talking millions of years, w/ movement of tectonic plates and such. So for right now, once an area is mapped, its mapped for good. HOWEVER. Maps may need to be redrawn if the quality of them sucks.