High Gain Portable GPS Antenna Array for Ionospheric Monitoring

Period of Performance: 05/22/1997 - 08/22/1999


Phase 2 SBIR

Recipient Firm

Navsys Corp.
14960 Woodcarver Road Array
Colorado Springs, CO 80921
Principal Investigator

Research Topics


The ionosphere affects GPS receivers by degrading the signal performance, in some cases causing loss of carrier lock, and by degrading the accuracy of differential corrections. As we enter the solar maximum years, these effects will become more severe, causing frequent GPS outages in the polar and equatorial regions and over the entire North American landmass when magnetic storms occur. These ionospheric anomalies can last for periods of up to two days, potentially having a massive effect on nationwide air transportation which relies on GPS operation for navigation and landing systems.A reliable ground monitoring system is essential to predict the occurrence of these events. To allow ionospheric data to be collected reliably even during large GPS signal fades, NAVSYS proposes to develop a high gain antenna array integrated with a digital GPS receiver for use as a benchmark for testing ionospheric monitoring receivers. An innovative digital beam steering approach is proposed that can be implemented using a low cost, PC-based architecture. This antenna array will significantly improve the performance of the IONO-AGR receiver allowing it to be used as a benchmark for measuring receiver performance in tracking low-power, scintillating GPS signals.