Citation
Abstract
Measurements have been conducted at two antenna ranges to assess whether internal range errors allow determination of the electrical location (phase center) of a Global Positioning System receiving antenna with submillimeter accuracy in the 1.1–1.6 GHz band. We first measured antennas in the tapered far-field chamber at Goddard Space Flight Center and later duplicated some of those measurements in the spherical near-field chamber at Nearfield Systems, Inc. (NSI). In general, the two ranges perform about equally well. Position errors due to thermal noise, mounting uncertainty, and instrumental drift are negligible at both. Multipath power at Goddard is about 40 dB below the direct signal but could significantly corrupt measurements at boresight angles near 90 deg. At NSI, multipath is about 50 dB below the direct signal after the application of software that detects it and reduces the effect. Direct comparison of phase centers calculated for identical configurations at the two ranges gives consistent results with a standard deviation of 0.58 mm. However, an offset of 6.5 mm remains unexplained. More detailed comparison of antenna phases over a range of directions also shows submillimeter consistency.
Details
- Volume
- 42-203
- Published
- November 15, 2015
- Pages
- 1–29
- File Size
- 3.4 MB