AE: Todd Humphreys’s Research Team Forges Ahead with Opportunities in Radionavigation, August 2011

Whether it’s investigating ways to preserve the security of GPS signals or developing new types of receivers, the field of radionavigation is ripe with possibility—and Dr. Todd Humphreys does not hesitate for a moment in defining how his research team fits into the mix. “What’s the next big thing in GPS?” he asks. “That’s what we’re trying to pursue. In fact, that’s what we’re trying to create.”

Continue reading the Aerospace Engineering Feature.

Dr. Humphreys Briefs USPTO, April 2011

Austin, TX — Dr. Todd Humphreys briefed the United States Patent and Trademark Office via webcast on the state of the art and future trends in radionavigation on Thursday, 14 April 2011. Examiners were present from the main USPTO site as well as satellite locations. Dr. Humphreys talked about:

  • Overview of Radionavigation/GPS
  • Advances in Weak-Signal GNSS Tracking and Indoor Navigation + Network-aided Navigation
  • Vector Tracking for Improved Navigation Accuracy and Robustness
  • Multipath Mitigation

You can download and view the presentation here [pptx].

You can read more about the presentation here.

Dr. Mark Psiaki visits RNL, april 2011

Austin, TX — Dr. Mark Psiaki visited RNL on 31 March and 1 April and gave two presentations:

  1. Nonlinear Model-Based Estimation Algorithms: Tutorial and Recent Developments [ppt] (BSEKF journal paper) at the Aerospace Department seminar series
  2. Civilian GPS Spoofing Detection based on Dual-Receiver Correlation of Military Signals [pptx] at the WNCG seminar series

UPDATE: Dr. Psiaki has written a paper on the Blind Tricyclist non-linear estimation problem available here [pdf]. Simulation functions and data are also available online.

RNL Briefs DHS and DoD Representatives on GPS Security and Integrity, March 2011

Austin, TX — Members of the Radionavigation Laboratory briefed visitors from the DHSUSCGNSWC, JNWC, and USSTRATCOM on several aspects of GPS security and integrity including: effects of GPS spoofing on power grid monitoringanti-spoofing techniques for civil GPS, and GPS interference detection and localization techniques.

Meeting Agenda and Participants 

Wardriving Captures Dynamic GPS and Cellular CDMA Signals, December 2010

Austin, TX — Members of the Radionavigation Laboratory went on a full day excursion to capture simultaneous GPS and Cellular CDMA spectrum via the lab’s powerful National Instruments radio frequency signal analyzers. Over 1.5 TB of spectral data were recorded at 37.5 MSps with the goal of characterizing dynamic GPS multipath, exploring tightly-coupled opportunistic navigation, and evaluating GPS jamming mitigation techniques. The data log files are available here for download. Interested parties can request this data for their own post processing needs.For a visual representation of the multipath encounterd, the data can be plotted in Google maps/earth. To see the visuals:1) go to the test listing.2) copy the “http:.// … .kml?rand=99” URL of the test to map3) open Google maps and paste the URL in the search bar

Nextgov: Researcher Reveals GPS Vulnerabilities, October 2010

“GPS timing signals that control the base stations in some cellular networks and other gadgets the size of small refrigerators that power the smart electric grid can fall prey to sophisticated spoofing attacks, according to a University of Texas researcher. Todd Humphreys, an assistant professor at the University of Texas Radionavigation Laboratory, said he successfully spoofed a type of laboratory time reference receiver of the code division multiple access network technology Sprint and Verizon use that relies on GPS time—with a transmitter he built for about $1,000.”

Continue reading the Nextgov article.