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A. Wieser, S. Niedermayr:
"Quality assessment of low-cost GPS antennas for use in geodesy";
Talk: QuGOMS'11, Garching bei München; 2011-04-13 - 2011-04-15.

The application of low-cost GNSS equipment in geodetic monitoring seems attractive because it may allow retrieving data continuously from a denser grid of monitoring points than using high-end equipment. Publications addressing this option have mostly been focusing on experimental investigations of consumer-grade L1 GPS receivers. This paper focuses on the quality of the antennas, which are a vital part of any GNSS-based observation and monitoring system.
Fundamental differences in design and capabilities of consumer grade antennas as opposed to low-cost antennas and high-end geodetic antennas are explained from a theoretical point of view, highlighting the impact on quality in terms of gain pattern, signal-to-noise ratio, phase center stability, and multipath rejection. The resulting effect on observation noise is predicted for the carrier-phase, pseudorange and Doppler observables. While it turns out that consumer grade antennas may not be suitable for geodetic applications associated with short site occupation times or kinematic rovers, there is a potential for use in monitoring if the daily repetition of similar error scenarios is exploited or if the daily motion on the order of a few centimeters per day is to be monitored. Experimental results from a field test involving four different types of antennas, among these two sub-100-Euro antennas, and results from an application to glacier flow rate monitoring are used to validate the prediction. The results are particularly relevant for use of GNSS nodes in sensor networks, where low-cost of the entire node can only be achieved if each component is low-cost while at the same time fulfilling all quality criteria.

GPS, antenna, low-cost equipment, noise

http://publik.tuwien.ac.at/files/PubDat_196728.pdf