On the extreme end, if you live in the countryside you can replace GPS entirely using celestial navigation/star tracking. This is commonly used for rockets and

On the extreme end, if you live in the countryside you can replace GPS entirely using celestial navigation/star tracking. This is commonly used for rockets and satellites but right now if you own a truck or pickup you can easily go completely off-grid by mounting a lens on the rooftop. E.g. http://nova.astrometry.net/ http://nova.astrometry.net/ For implementing the system on an embedded device e.g. toy drone, raspberry pi etc., the main data structure you want is a k-d tree together with some sort of evergreen star chart (it doesn't have to be extremely evergreen, current astronomy libraries can easily predict orbits for a couple decades without significant skew/deviation unless you are are aiming for centimeter level geolocation accuracy). For the hardware you can either use existing consumer-grade stuff followed by a ton of image processing with ML as suggested above or you can use a industrial grade tracker which easily exceeds 4 figures. https://blog.satsearch.co/2019-11-26-star-trackers-the-cutting-edge-celestial-navigation-products-available-on-the-global-space-marketplace https://blog.satsearch.co/2019-11-26-star-trackers-the-cutti... It's a pretty fun weekend project. Here are some links to get started: https://github.com/mrhooray/kdtree-rs https://github.com/mrhooray/kdtree-rs https://github.com/astronexus/HYG-Database/blob/master/README.md https://github.com/astronexus/HYG-Database/blob/master/READM... Instead of jacking up your truck, add celestial nav to it. Nothing screams freedom and independence more than cutting dependency on state-funded satellite systems. Caveats: needs more signal processing during daytime, fallback to inertia navigation when it is cloudy.