Scientists develop underground navigation system using cosmic rays

Scientists may have found a way to launch a navigation system underground as they have revealed that it is effectively possible by using showers of particles that are formed when cosmic rays collide with the atmosphere of Earth, according to research published in iScience.

The subatomic particle rays named — muons — coming down on Earth’s surface allowed scientists to determine the basement position of an individual.

These rays come from distant space objects such as supernovas or the collision of particles with the sun on Earth. These can go under the ground and are reported to be harmless.

It may be a breakthrough and can be used for mining, deep sea exploration and other areas where GPS could not work.

“Cosmic ray muons fall equally across the Earth and always travel at the same speed regardless of what matter they traverse, penetrating even kilometres of rock,” said physicist Hiroyuki Tanaka of the University of Tokyo in Japan

“Now, by using muons, we have developed a new kind of GPS, which we have called the muometric positioning system (muPS), which works underground, indoors, and underwater.”

Similar particles were used in Egyptian pyramids for navigation.

It is not used as a GPS satellite but four muon-detecting reference stations are placed above ground, and receiver, either on a person or underground.

“As a shower of muons falls, they first travel through the reference detectors before making their way to the receiver. The time lag between the reference detectors and the receivers allows for trilateration, giving the receiver’s coordinates. However, the first muPS system had to be wired, which is not very practical for someone moving about. Now, the team has taken the system wirelessly,” according to Science Alert.

“The reference detectors and the receiver were all connected to a synchronised, precision quartz clock. One of the reference detectors was placed on the sixth floor of a building while a person carrying the receiver moved around in the basement. The new system is called the muometric wireless navigation system (MuWNS).”

Tanaki said: “The receiver’s coordinates were not tracked in real-time; the team took measurements and used them to reconstruct the route the person took through the basement corridors. They were able to do so with reasonable accuracy, but it could get better.”

“The current accuracy of MuWNS is between 2 meters and 25 meters (6.5 and 82 feet), with a range of up to 100 meters, depending on the depth and speed of the person walking. This is as good as, if not better than, single-point GPS positioning aboveground in urban areas,” he said.

“But it is still far from a practical level. People need 1-meter accuracy, and the key to this is time synchronization.”

“With these new results,” wrote researchers, “It is clear that with further improvements, MuWNS can be adapted to improve autonomous mobile robot navigation, positioning, and other underground and underwater practical applications.”