High-Gain Advanced GPS Receiver for Precision GPS Applications
Abstract
NAVSYS has developed a GPS receiver, the HAGR (High-gain Advanced GPS Receiver), which uses digital beam steering to increase the precision of the GPS observations. In this paper, the HAGR is described and test data is included showing its enhanced performance for high accuracy scientific applications. When operating in a differential or kinematic positioning mode, HAGR provides low noise observations of the pseudo-range and carrier-phase data. By coherently combining signals from as many as 16 antenna elements, the gain to each satellite tracked can be increased by over 10 dB. Moreover, the digital beam steering approach used also acts to reduce the errors contributed by multipath effects. Test data is presented on the HAGR measurement accuracy for high accuracy scientific applications. In this paper, the GPS carrier-phase time transfer technique is described and a discussion is included on the error components that currently limit the time-transfer accuracy using this method. Sub-nanosecond time transfer capabilities are expected using GPS carrier-phase observations. Testing to date has shown that conventional GPS receivers introduce significant time offsets in the carrier phase. These offsets are on the order of 1-2 nanoseconds and currently dominate the error budget when performing carrier-phase time transfer. Test data is also presented from the HAGR showing the accuracy of the code and carrier phase observations for time transfer applications.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 2000
- Accession Number
- ADA476342
Entities
People
- Alison Brown
- Ed Powers
- Randy Silva