Geomagnetic Navigation Is Replacing GPS. Here’s How It Actually Works.

GPS has three major blind spots: underwater, deep indoors, and in conflict zones where it can be jammed or spoofed. Geomagnetic navigation offers a solution using the magnetometer already present in modern smartphones. Every location has a unique magnetic fingerprint shaped by local steel, concrete, and underground infrastructure. Companies like Astronav and Hydronics are mapping these fingerprints and using neural networks to enable on-device indoor positioning accurate to under a meter — no satellites or external infrastructure required. The indoor positioning market is forecast to reach $150 billion by 2030.