Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

GPS Jamming and GPS Carrier-Phase Time Transfer

Published

Author(s)

Jian Yao, Marc A. Weiss, Charles Curry, Judah Levine

Abstract

This paper studies the impact of GPS jamming on GPS carrier-phase time transfer. To study this issue, at NIST, we have installed a commercial GPS jamming detector since 2014 April. During 2014 April – 2015 April, the detector detected more than 100 jamming events, though there had been a few outages of jamming detection. The jamming events usually last for less than 2 min. We find that almost all jamming events lead to a significant drop in the L1 signal-to-noise ratio (SNR) for all observable GPS satellites. Another thing we notice is that the 3 GPS receivers which are closer to Broadway, a main street in Boulder, Colorado, are more likely to be jammed. This indicates that the jamming source may come from cars passing by. Although a jamming event causes a significant drop in L1 SNR, the GPS receiver can still track the GPS satellites properly for most cases. However, sometimes, the jamming can be too strong and then a GPS receiver may lose track of some GPS satellites. This leads to a GPS-data anomaly. Because of this anomaly, the carrier-phase time transfer processing re-estimates the phase ambiguities at the anomaly. Thus, there is often a time discontinuity at the anomaly. The discontinuity ranges from a few hundred picoseconds to a few nanoseconds. Then the next question is what we shall do when a jamming event occurs? Our earlier study [1] shows that the 9th-order polynomial curve fitting for the code and phase measurements can repair a short-term data anomaly (
Proceedings Title
Precise Time and Time Interval Meeting 2016
Conference Dates
January 25-28, 2016
Conference Location
Monterey, CA
Conference Title
The Precise Time and Time Interval Systems and Applications (PTTI) meeting

Keywords

GPS carrier-phase time transfer, GPS jamming

Citation

Yao, J. , Weiss, M. , Curry, C. and Levine, J. (2016), GPS Jamming and GPS Carrier-Phase Time Transfer, Precise Time and Time Interval Meeting 2016, Monterey, CA (Accessed December 6, 2024)

Issues

If you have any questions about this publication or are having problems accessing it, please contact reflib@nist.gov.

Created January 25, 2016, Updated February 19, 2017