Feb. 24: Adaptive Antenna Arrays for Precision GNSS Receivers

Speaker: Dr. Andrew J. O’Brien, ElectroScience Laboratory

Date: Thursday, February 24, 2011 at 1:30 p.m.

Location: ElectroScience Laboratory Classroom, 1320 Kinnear Rd., Columbus, OH, 43212

Abstract:
In recent years, global navigation satellite systems (GNSS) have revolutionized precise positioning, navigation, and timing. In order to protect critical military and civilian GNSS receivers from radio-frequency interference and jamming, adaptive antenna arrays are playing an increasingly important role. The reception pattern of these antenna arrays is controlled via adaptive digital filters, which perform beamforming/null steering in satellite and interference directions. While the adaptive processing in these antenna arrays had been widely used for radar and communications applications, it was not initially understood how to optimize these systems to meet the specialized requirements of GNSS receivers. This presentation highlights the contributions the author has made to the optimization adaptive antenna electronics for GNSS applications. These contributions include the derivation and implementation of optimal interference suppression algorithms, the development of approaches for preventing the adaptive antenna from introducing errors into the GNSS receiver measurements, and the precise, automated calibration of adaptive antennas. Ultimately, the combination of these capabilities allows the use of adaptive antennas in the most precise and demanding GNSS applications. Simulation results are presented which demonstrate performance the proposed techniques using adaptive antennas in the presence of interference. Furthermore, this presentation also discusses current research being performed with regard to these systems. This includes the use of GNSS antenna arrays for interference geo-location, the tight integration of GNSS receivers with antenna electronics, and the mitigation of platform multipath effects of GNSS antennas mounted on complex platforms, such as aircraft. Finally, this presentation will touch upon potential future directions.

Bio:
Dr. Andrew J. O'Brien received his B.S., M.S. and Ph.D. degrees in Electrical and Computer Engineering from the Ohio State University. From 2005 until 2009, he was a Graduate Research Associate at the Ohio State University ElectroScience Laboratory. His graduate research dealt extensively with topics involving adaptive antenna arrays for GNSS receivers, including modeling, simulation, and analysis of interference suppression algorithms, characterization their precise effects on GPS receiver measurements, and the simulation of these antennas on complex platforms. Currently, he is a Postdoctoral Researcher at the ElectroScience Laboratory. His research interests include GNSS receivers, antenna arrays, adaptive filtering, geo-location, and antenna calibration.