Lawrence Livermore National Laboratory



Willem De Vries

Overview

Over the last decade, use of space-based navigation systems, such as the Global Positioning System (GPS), on cell phones and other portable electronics has expanded beyond their original military positioning, navigation, and timing (PNT) applications. Significant portions of the economy rely on the availability of positioning information, implicitly assuming few, if any, service interruptions. However, the military has to anticipate scenarios in which signal jamming results in GPS being partially or completely unavailable because the resultant loss of PNT information would severely impact military operations across all domains. In fact, the U.S. Navy has reintroduced celestial navigation classes for their academy students to retain foundational navigation knowledge (Arneson 2015). Such navigation typically uses a sextant to obtain latitude coupled with accurate clocks to obtain longitude.

Our project achieved a much more precise geolocation based on stellar observations than sextants, allowing location determination accuracy high enough to be operationally relevant. Our system uses the known positions of celestial objects coupled with an accurate (quartz) clock to determine geodetic positions on Earth (or, using the same principle, on the Moon and Mars for space missions). The system provides location information anywhere on Earth to better than 30 meters absolute, or 10 meters relative, providing viable alternative pathway to GPS-less location determination. Systems such as these could provide resilient capabilities for the military in signal-jamming environments. The method is universal enough to be applied to any celestial body for which we have determined the local gravity field to a high enough degree (e.g., Hirst et al. 2012 for Mars).

Impact on Mission

The project leveraged Lawrence Livermore National Laboratory's core capabilities in optical science and technology and Livermore technologies developed under the auspices of Livermore's Space Science and Security program. The work aligns with Livermore's defense mission area by contributing innovative science and technology to the Department of Defense. The PI has been asked to join the Defense Science Board subcommittee on PNT control, further raising outside awareness of Livermore's space science and security expertise. Industry partners have shown interest in elements of the work that support commercial small satellite programs.

References

Arneson, D. 2015, Oct 15 "Charting a New Course: Celestial Navigation Returns to USNA." http://www.navy.mil/submit/display.asp?story_id=91555

Hirst, C., Claessens, S. J., Kuhn, M., and Featherstone, W. E. 2012, "Kilometer-resolution Gravity Field of Mars: MGM2011." Planetary and Space Science, 67, volume 1, pp 147–154