The underground compass replaces the GPS satellites

British researchers are testing a quantum train tracking system under the London Underground, which will replace the tracking system with satellites.

According to Interesting Engineering, researchers at the Cold Matter Center at Imperial College London are moving some special equipment underground in London. This equipment includes lasers, rubidium atoms and a vacuum chamber, which are used to build and test a quantum compass in the city’s train service.

The Global Navigation Satellite System (GNSS) is a vital tool in today’s transportation industry. This system helps to determine the exact location of the vehicle and calculate the time to reach the destination when traveling by road, sea or air, which is a critical feature to maintain the supply chain.

However, the entire navigation system is subject to jamming by enemies as well as bad weather. Even if this service is supposed to improve in urban areas with tall buildings and other structures, this demt will only be activated for some situations of underground or underwater transportation.

In this regard, Imperial College London researchers are developing a quantum compass that accurately determines the exact location of an object by relying on the behavior of substances smaller than atoms.

Such a system does not require satellites and can work effectively underground and underwater. Interestingly, the researchers don’t have to invent a completely new device to achieve this, rather they work with the accelerometer sensor that is present in all mobile phones.

Even if city services that are full of tall buildings and other structures are to be upgraded, said service will only be efficient for some modes of transportation that operate underground or underwater.

This sensor can calculate the rate of change of the speed of the object over time. With the help of this information, as well as the data of the starting point of the object’s movement, researchers can determine its exact position at any time.

The only challenge to this idea is that mobile speedometers are not accurate over long periods of time, so the researchers had to create a more accurate version with the help of quantum mechanics.

When atoms are supercooled, they act like waves. Using information about their motion, physicists can measure changes in the device’s position.

In this regard, the researchers used rubidium atoms in their setups as well as a range of lasers to cool them down to zero temperature. All these settings were placed inside the vacuum chamber and the results obtained were consistent with the laboratory conditions. Researchers are working in the London underground to test this equipment. This equipment is used to make a separate device that is able to measure the exact speed of the train and its location.

Tests have been carried out underground on test trains and, if successful, will be used to track the 540 trains that run underground during London’s rush hour traffic.