Humphreys and his team in the Radionavigation Lab have built a low-cost system that reduces location errors from the size of a large car to the size of a nickel — a more than 100 times increase in accuracy. Humphreys collaborated with another D-STOP researcher, Professor Robert W. Heath from the Department of Electrical and Computer Engineering, and graduate students on the new technology, which they describe in a recent issue of GPS World.
Centimeter-accurate positioning systems are already used in geology, surveying and mapping, but the survey-grade antennas these systems employ are too large and costly for use in mobile devices. The breakthrough by Humphreys and his team is a powerful and sensitive software-defined GPS receiver that can extract centimeter accuracies from the inexpensive antennas found in mobile devices — such precise measurements were not previously possible. The researchers anticipate that their software’s ability to leverage low-cost antennas will reduce the overall cost of centimeter accuracy, making it economically feasible for mobile devices.
Humphreys and his team have spent six years building a specialized receiver, called GRID, to extract so-called carrier phase measurements from low-cost antennas. GRID currently operates outside the phone, but it will eventually run on the phone’s internal processor.
To further develop this technology, Humphreys and his students recently co-founded a startup, called Radiosense. Humphreys and his team are working with Samsung to develop a snap-on accessory that will tell smartphones, tablets and virtual reality headsets their precise position and orientation. Samsung provided funding to Humphreys’ Radionavigation Lab at UT Austin for the centimeter-accurate global positioning system research and plans to continue funding related basic research.
The researchers designed their system to deliver precise position and orientation information — how one’s head rotates or tilts — to less than one degree of measurement accuracy. This level of accuracy could enhance VR environments that are based on real-world settings, as well as improve other applications, including visualization and 3-D mapping.
Additionally, the researchers believe their technology could make a significant difference in people’s daily lives, including transportation, where centimeter-accurate GPS could lead to better vehicle-to-vehicle communication technology.
“If your car knows in real time the precise position and velocity of an approaching car that is blocked from view by other traffic, your car can plan ahead to avoid a collision,” Humphreys said.
In other applications, D-STOP researcher Jennifer Duthie said her team is hoping to pilot a project this summer to gather data from the movement of bicycles and motor vehicles using GPS.
“We’re hoping to do a pilot this summer where we put [the technology] on a few bicycles and just see it how we can use this data for better bicycle planning,” Duthie said. “You can extract certain driver characteristics, and get real insight into how people make turns.”
The University of Texas at Austin is committed to transparency and disclosure of all potential conflicts of interest. All UT investigators involved with this research have filed their required financial disclosure forms with the university. Todd Humphreys and three of his graduate students — Andrew Kerns, Daniel Shepard and Kenneth Mark Pesyna Jr.— own equity positions in Radiosense LLC, a company they created to market high-precision, low-cost GPS positioning. The company is based on technology created in Humphreys’ lab that Radiosense is licensing from UT, working with the university’s Office of Technology Commercialization.