  The fundamental principle of satellite or node-based positioning involves
triangulating the receiver's coordinates through the intersection of spatial
distances. Recent advancements in hybrid wireless networks have yielded
high-precision positioning at decimetre-level (wavelength-level) (Nature 611,
473-478 (2022)), approaching the resolution limits in free space. Here, we
present a three-dimensional (3D) super-resolution positioning paradigm in free
space by utilizing a novel kind of topologically structured pulses, toroidal
electromagnetic pulses (Nat. Photonics 16(7), 523-528 (2022); Sci. Adv. 10(2),
eadl1803 (2024)). Excited by the recent compact generator of toroidal pulses
and their sophisticated topological and nonseparable structures, we demonstrate
that the space-time nonseparability and skyrmion topology inherent in toroidal
pulses can be harnessed to achieve freespace microwave 3D positioning with
super-resolution accuracy, reaching the centimeter level, using a single
emitting antenna. This work opens up new avenues for exploring the potential
applications of topological electromagnetic pulses including but not limited to
positioning, imaging, and sensing technologies.
