Given the threats to GNSS from spoofing and jamming, the search is on for alternative sources of PNT data.
Diverse animals — such as sea turtles, spiny lobsters, and birds — use magnetoreception for orientation and navigation. However, while animals likely perform wayfinding using the direction of the magnetic field, similarly to how humans use a compass, high-resolution maps used in conjunction with atomic instruments enable us to perform absolute positioning to tens of meters, explained Major Aaron Canciani.
Canciani, an assistant professor of electrical engineering at the Air Force Institute of Technology, has been designing algorithms for MAGNAV flight testing for several years.
Earth’s crustal magnetic field varies from location to location as much as topographic features do and, like them, it changes very little over time. However, unlike topographic features, which only occur on the third of the planet’s surface covered by land, magnetic variations also occur on the oceans. This makes them potentially very useful as landmarks to the Navy and Air Force. Magnetic variations have the additional benefit that they cannot be jammed or spoofed.