Engineering experts have discovered a mechanism for correctly locating a place on Earth using signals emitted by Starlink internet service satellites, similar to how GPS works. It’s the first time that researchers outside of SpaceX have used the Starlink system for navigation.
Elon Musk’s SpaceX sent the Starlink satellites into orbit with the goal of providing broadband internet access to remote regions around the world. The researchers pinpointed a place on Earth within 8 meters using data from six Starlink satellites.
Their findings, which were presented at Institute of Navigation GNSS yearly meeting in St. Louis today (Sept. 22, 2021), could give a promising option to GPS. Their findings is going to be published in IEEE Transactions on the Aerospace and Electronic Systems in the near future.
The researchers didn’t need SpaceX’s help using the satellite signals. They made it clear that they didn’t have access to actual data sent by the satellites, only information about their location and movement.
“We eavesdropped on the signal, then designed sophisticated algorithms to pinpoint our location, and we demonstrated that it works with great accuracy,” said Zak Kassas, who serves as the director in charge of The Ohio State University’s Center for the Automated Vehicles Research with the Multimodal Assured Navigation (CARMEN), which is a multi-institution transportation facility.
“And, even though Starlink was not built for navigation, we demonstrated that components of the system could be learned well enough to be used for navigation.”
CARMEN is among the 4 University Transportation Centers recently awarded by the US Department of Transportation. Kassas is an associate professor of the electrical and computer engineering at the Ohio State University as well as an associate professor of the electrical and computer engineering at University of California, Irvine.
Kassas and his team researched the Starlink system and evaluated the signals sent by the satellites for this study. They devised an algorithm that can be able to identify a position on the Earth by combining the signals of many satellites. Then they built an antenna on the UCI campus and tried to locate its location using the network.
They used Starlink to pinpoint the antenna’s placement to within 7.7 meters. On the other hand, GPS can usually pinpoint a device’s location within 0.3 to 5 meters. Kassas said the team has employed similar techniques with other low-Earth-orbit satellite constellations, but with much less precision, locating places within 23 meters. The team has been collaborating with the United States Air Force to locate the whereabouts of high-altitude aircraft; utilizing land-based cellphone signals, they got within 5 meters, according to Kassas. SpaceX has 1,700 satellites in the Earth’s low orbit, which means they orbit the planet at a distance of around 1,200 kilometers from the surface. SpaceX intends to deploy over 40,000 satellites in total.