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Navigation systems today depend heavily on satellite signals, but those signals are not always reliable. GPS can be jammed or spoofed, and in certain environments, such as underwater, underground, or in deep space, it may not be available at all. For platforms that require continuous and precise positioning, this creates a critical vulnerability.
A new Chinese approach focuses on improving the accuracy of onboard timekeeping, which is the foundation of navigation systems. Instead of relying solely on external signals, advanced clocks can calculate position by measuring time, speed, and direction. The more precise the clock, the more accurate the navigation becomes.
Researchers have developed a new type of crystal designed to support next-generation nuclear clocks. According to Interesting Engineering, unlike conventional atomic clocks, which rely on electron behavior, nuclear clocks measure vibrations within an atom’s nucleus. These vibrations are more stable and less affected by environmental factors such as temperature, magnetic fields, or mechanical disturbance.
The key challenge has been generating the specific ultraviolet light needed to measure these nuclear transitions. The new crystal addresses this by converting laser light into extremely short ultraviolet wavelengths. In testing, it achieved a wavelength of approximately 145 nanometers, closer than previous attempts to the level required for thorium-based nuclear clock systems.
This improvement brings the concept of ultra-precise, compact clocks closer to practical use. Such systems could enable “dead reckoning” navigation, where a platform continuously calculates its position without relying on external signals. Over time, this method could be combined with other references, such as celestial or radio sources, to further improve accuracy.
From a defense perspective, the implications are significant. Systems that do not depend on GPS are less vulnerable to jamming or interference, making them more resilient in contested environments. Submarines, for example, could maintain accurate positioning without surfacing, while other platforms could operate with greater independence from external infrastructure.
Beyond defense, the technology could support deep-space missions, where satellite navigation is not available. As precision timing continues to improve, navigation systems may become increasingly self-reliant, reducing dependence on external signals and enhancing operational flexibility across multiple domains.
