Citation
Abstract
We report here results of single-baseline very long baseline interferometry (VLBI) observations of pairs of quasars, carried out at 8.4 GHz on the Madrid–Goldstone baseline with Deep Space Network (DSN) 34-m antennas. Using a fast-switching technique, we are able to successfully carry out phase connection for each observation, resulting in relative astrometric precision of a few picoseconds, equivalent to an angular precision of ∼0.2 nanoradians. In this article, we will discuss the potential of phase delay observations and the technique used to reliably connect phase across observations of calibrator and program source. We will show that by reducing both the temporal and angular separation between the calibrator and program source (either a natural radio source or a spacecraft) we are able to minimize and cancel many sources of common mode error, such as media variations and instrumental changes, as well as errors associated with lack of knowledge of the exact observing geometry. We also will discuss the implications of these results for potential gains in improved accuracy for measurements of spacecraft angular position at the DSN.
Details
- Volume
- 42-172
- Published
- February 15, 2008
- Pages
- 1–17
- File Size
- 206.6 KB