Citation
Abstract
A new media calibration system is currently being implemented at DSS 25 that is intended to calibrate the delay of radio signals due to the neutral atmosphere, both the static dry and static and fluctuating wet components of this delay. In particular, the system will calibrate the fluctuations in path delay due to atmospheric water vapor that we believe will dominate the error budget for several radio science and radio astronomy experiments. The first user of this system will be the Gravitational Wave Experiment (GWE) with the Cassini spacecraft. The system consists of a water vapor radiometer (WVR) of a new design (i.e., the A-series), a microwave temperature profiler (MTP), and a package of instruments that sense surface meteorology. In order to demonstrate the performance of the media calibration system, we have installed two of them, one near DSS 13 and one near DSS 15. We operated these two radio antennas as an interferometer and compared the estimates of path delay provided by the media calibration system to the delay fluctuations seen by the interferometer. In this article, we describe the instrumentation, observing strategy, data analysis procedures, and weather conditions for 29 interferometer experiments that started on August 17, 1999, and ended May 18, 2000. Our goal is to demonstrate that the new media calibration system can meet or exceed an Allan standard deviation of 3 £ 10¡15 on time scales of 1,000 to 10,000 s, as required by the Cassini GWE.
Keywords
Details
- Volume
- 42-145
- Published
- May 15, 2001
- Pages
- 1–20
- File Size
- 674.1 KB