GPS Signal Environment Passive Monitor System

Paul Manning, Bette Winer, Wilbert Mason, Joseph Ruggiero and Philip McCarty

Abstract:	This paper describes a GPS Signal Passive Monitor System developed at the Volpe National Transportation Systems Center (Volpe Center) under sponsorship of the Federal Aviation Administration (FAA), and currently installed in a Piper Aztec aircraft. This system was developed to allow: 1) the gathering of many hours of data that can document receiver performance and the GPS Signal- to-Noise ratio, one measure of the RF environment, in the National Airspace System (NAS); and 2) a preliminary characterization of any interference event the aircraft might encounter. When proven effective, integrated monitor and evaluation software providing for alarms to the pilot will be made available to the FAA for use on its flight check aircraft. The monitoring system requires no pilot action, being automatically activated whenever the aircraft’s avionics receive power. The monitor is composed of off-the-shelf components including: a GPS receiver which provides information about the signal-to-noise ratio for each satellite in view, a laptop personal computer (PC), control relays and power converters. The data collected include parameters such as time, position (lat, long), quality (tracking, not tracking), and satellite signal-to-noise level. The data are periodically transferred to diskettes for post-processing. This paper describes the GPS Passive Monitor System, discusses data analysis, and presents the results of 80 flight hours that were made over New England and the eastern seaboard from Massachusetts to Florida. There were no incidents of loss-of-lock due to RF interference (RFI) during this period despite close approaches to potentially interfering TV transmitters. The only incident of loss-of-lock was traced to aircraft blockages of multiple satellites during extreme maneuvers.
Published in:	Proceedings of the 1996 National Technical Meeting of The Institute of Navigation January 22 - 24, 1996 Loews Santa Monica Hotel Santa Monica, CA
Pages:	655 - 658
Cite this article:	Manning, Paul, Winer, Bette, Mason, Wilbert, Ruggiero, Joseph, McCarty, Philip, "GPS Signal Environment Passive Monitor System," Proceedings of the 1996 National Technical Meeting of The Institute of Navigation, Santa Monica, CA, January 1996, pp. 655-658.
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In