Aboard every satellite of the Global Positioning System (GPS) is an incredibly precise atomic clock – a clock based on measuring the unchanging structure of atoms. By using timing and location signals from at least four satellites, a GPS user can pinpoint their exact location on Earth. However, these GPS signals are extremely weak, meaning interference with GPS signals is surprisingly easy to achieve. Rates of GPS signal spoofing and jamming are increasing, with critical infrastructure becoming increasingly affected.
By improving the performance of these clocks and reducing their form factor, the next generation of GPS can have higher accuracy with increased resilience to interference. Such atomic clocks also have the potential to allow accurate navigation without GPS entirely, at least for a time!
Dr Sarah Scholten’s research aims to make this reality. By harnessing lasers to do this same measurement of atoms, the performance of this next generation of `optical atomic clocks’ can be hundreds to thousands of times better than those on the current GPS system.
Dr Scholten has not only developed such a clock, but has successfully demonstrated it outside of her laboratory, with the project’s commercial partner further developing this prototype for space launch later in 2025. Dr Scholten is now focused on improving the performance of this technology even further, while simultaneously refining the form factor, to make GPS interruption a thing of the past.