October 1, 2015

About the Presentation

Global Navigation Satellite System (GNSS) technology is now ubiquitous in smartphones and tablets, and yet the underlying positioning accuracy of consumer-grade GNSS receivers has stagnated over the past decade. The latest clock, orbit, and atmospheric models have improved receiver ranging accuracy to a meter or so, but receiver-dependent multipath continues to produce errors in current consumer devices. Multipath occurs when the direct path to the receiver is blocked and the signal from the satellite is reflected by an object, resulting in distance calculation errors.

Currently, the primary barrier to performing centimeter-accurate carrier-phase-differential GNSS (CDGNSS) positioning on smartphones and other consumer handheld devices is their low-cost, low-quality GNSS antennas that have poor multipath suppression. The time correlation of multipath errors and their magnitude significantly increases the initialization period of GNSS receivers using low-cost antennas.

This presentation focused on techniques for reducing the initialization time for centimeter-accurate positioning on mobile devices. It further examined technical and market prerequisites for a vast expansion of precise positioning in mainstream markets—for globally registered augmented and virtual reality, improved safety for semi-autonomous and autonomous vehicles, and crowd-sourced three-dimensional mapping.

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About the Speaker

Todd E. Humphreys

Todd E. Humphreys¬†is an associate professor in the Department of Aerospace Engineering and¬†Engineering Mechanics at the University of Texas at Austin and director of the UT Radionavigation¬†Laboratory. He specializes in the application of optimal detection and estimation techniques to problems in satellite navigation, autonomous systems, and signal processing. His recent focus has been on secure perception for autonomous systems, including navigation, timing, and collision avoidance, and on centimeter-accurate location for the mass market. Dr. Humphreys received the University of Texas Regeants’ Outstanding Teaching Award in 2012, the National Science Foundation CAREER Award in 2015, and the Institute of Navigation Thurlow Award in 2015. He received a B.S. and M.S. in electrical and computer engineering from Utah State University and a Ph.D. in Aerospace Engineering from Cornell University.