Every time we drive on an unfamiliar street, use a delivery service, or check an online map, we are reminded of the essential role GPS has in our modern lives. Behind the scenes, GPS is also vital to topics like national security (almost all military operation equipment utilizes GPS), air travel, emergency rescue and monitoring weather/environmental hazards. However, as anyone will notice when they drive into an underground parking area or enter a tunnel, GPS stops working in some areas. Also, since GPS signals are susceptible to being jammed or spoofed, the positioning data could be compromised by malicious third parties.
muPS works in environments where GPS fails (for example: underground, underwater, indoors, at high altitudes, and in areas with too many obstructions). It uses cosmic ray muons, naturally occurring signals generated in the atmosphere from galactic cosmic rays. Muons survive in areas that GPS signals cannot. Additionally, the signals are robust enough to block any attempts to tamper with muon detection.
muPS is dated back 2020 when it first appeared in “Muometric positioning system (μPS) with cosmic muons as a new underwater and underground positioning technique”. The initial model needed to be wired to receivers but eventually a wireless model called MuWNS was proposed and demonstrated. In order to overcome the limitations of MuWNS, Vector muPS was proposed and the most recent model called MuWNS-V yields a centi-meter level navigation accuracy.
The upshot is that by using muons for positioning, many new possibilities open up. Remote automation of underground/indoor/underwater robots, underwater Arctic navigation, monitoring seafloor volcanoes, and mine/tunnel mapping are examples of potential applications.
More information:
TIME Best Inventions of 2023 article
University of Tokyo press release
“Miikshi Cosmic Rays (Global Positioning/Navigation)”: Educational video about muPS