GPS and ionospheric scintillations
Article first published online: 7 SEP 2007
Copyright 2007 by the American Geophysical Union.
Volume 5, Issue 9, September 2007
How to Cite
2007), GPS and ionospheric scintillations, Space Weather, 5, S09003, doi:10.1029/2006SW000260., , and (
- Issue published online: 7 SEP 2007
- Article first published online: 7 SEP 2007
- Manuscript Accepted: 21 APR 2007
- Manuscript Revised: 12 APR 2007
- Manuscript Received: 15 JUN 2006
- ionospheric irregularities;
 Ionospheric scintillations are one of the earliest known effects of space weather. Caused by ionization density irregularities, scintillating signals change phase unexpectedly and vary rapidly in amplitude. GPS signals are vulnerable to ionospheric irregularities and scintillate with amplitude variations exceeding 20 dB. GPS is a weak signal system and scintillations can interrupt or degrade GPS receiver operation. For individual signals, interruption is caused by fading of the in-phase and quadrature signals, making the determination of phase by a tracking loop impossible. Degradation occurs when phase scintillations introduce ranging errors or when loss of tracking and failure to acquire signals increases the dilution of precision. GPS scintillations occur most often near the magnetic equator during solar maximum, but they can occur anywhere on Earth during any phase of the solar cycle. In this article we review the subject of GPS and ionospheric scintillations for scientists interested in space weather and engineers interested in the impact of scintillations on GPS receiver design and use.