A new approach for capturing data produced by aircraft sensors could help the Department of the Air Force (DAF) make more efficient use of its warfighting resources.
Dr. Robert Bedford, a member of the integrated photonics and quantum materials research staff in the Air Force Research Laboratory (AFRL) Materials and Manufacturing Directorate (RX), has been working with a suite of collaborators to investigate enhanced sensing capabilities. He and research collaborator Dr. Michael Slocum recently received a patent from the U.S. Patent and Trademark Office related to innovations achieved while conducting this work.
Dr. Bedford’s research focuses on magnetic field sensing technology. According to him, there are several ways that a pilot might conduct PNT (Positioning, Navigating, and Timing) activities in areas where an adversary has jammed Global Positioning System (GPS) capabilities. Some of them – such as looking for landmarks on the ground – are decidedly low-tech, as well as of limited use in the dark of night. Using star trackers, another common method for determining aircraft position and direction, is also not ideal when flying in inclement weather.
A more innovative method, however, makes use of the magnetic field naturally produced by the Earth. Ferrous materials in Earth’s crust impart small perturbations onto the core magnetic field. Because the distribution of these materials within the crust is not uniform, researchers can map the varied distortions created by them. Knowledge of this unique distribution can then tell pilots their position as they fly above the ground.
According to Dr. Bedford, specialized sensors installed aboard aircraft can sense these distortions in the magnetic field. These sensors rely on nitrogen-vacancy centers embedded within diamond crystal lattices. Infusing the diamond lattices with a slight radio frequency and then shining green laser light upon them creates, in turn, red light. The strength of the “photoluminescence” of this red light then indicates the magnitude and direction of the magnetic field surrounding the sensor, which can be used to determine aircraft position.
As Dr. Bedford also noted, the magnetic field sensing capability is very difficult – if not practically impossible, in fact – for adversaries to defeat. Short of completing large-scale terraforming of vast tracts of land, which would be extremely expensive and disruptive, there is virtually no way for adversaries to camouflage the magnetic field distortions created by iron deposits. This fact makes the technology extremely versatile and ensures that DAF’s pilots will have reliable methods of navigation available to them, even when flying deep into enemy territory.
However, although the affiliated research community has been working on refining the technology for more than fifteen years, Dr. Bedford emphasized that there are nonetheless substantial problems related to current capabilities. The primary challenge he identified is that when red light leaves the diamond, it emits in all directions and can be difficult, if not impossible, to collect in its entirety. When using this method, then, sensors must be relatively large to compensate for the inefficiencies in collecting red light.
Dr. Bedford and Dr. Slocum’s recent patent is related to their work developing a new method for collecting sensor data. This method, which Dr. Bedford calls the “absorption-based approach,” ignores red light and focuses on infrared light instead. The material absorption of the infrared light is also sensitive to the magnetic field, but absorption is far more directional, resulting in high-performance readout at smaller scales – potentially, in fact, by a factor of up to five hundred times! The recently patented technology strengthens this approach by mitigating noises associated with the measurement process to achieve results as close to theoretical performance ceilings as possible.
According to Dr. Bedford, this exponential increase in efficiency could have significant implications for DAF, especially regarding how its aircraft use resources. Using this technology, positional sensors could be constructed to be far smaller than they are now – and having smaller, lighter positional sensors means that the aircraft must dedicate less power to navigation. This means, in turn, that aircraft could then be equipped with more sensors of other varieties. Additionally, power saved on operating positional sensors could be sent to the engine, the weapons systems, or some other component of the aircraft to improve performance. In sum, the invention could help DAF make its aircraft more efficient, more effective, and more prepared for the mission ahead.
Dr. Bedford’s patent application was facilitated by AFRL/RX’s Office of Research and Technology Application (ORTA). DAF ORTAs protect DAF’s interests as related to new discoveries achieved in DAF research laboratories. DAF ORTAs work with DAF scientists and engineers to navigate the patent application and issuance process, ensuring that DAF’s intellectual property interests are secured. After patent issuance, many technologies are licensed to external entities for further development, and DAF ORTAs also facilitate this process. DAF ORTAs coordinate their activities with the DAF Technology Transfer and Transition (T3) Program Office, which oversees individual ORTAs and performs ORTA functions for DAF laboratories lacking a designated ORTA.
United States Patent and Trademark Office Patent #12,436,208