Citation
Abstract
Mounting a water vapor radiometer (WVR) on the back of a DSN antenna subreflector would allow calibration of delay fluctuations on timescales of 10-100 s, which is not possible with the current generation of ofi-axis WVRs. This calibration would improve the accuracy of short-timescale radio science experiments with planetary spacecraft. It would greatly improve the coherence of 86-GHz very long baseline interferometry (VLBI), allowing detection of substantially weaker sources, and giving much better amplitude calibration (i.e., higher dynamic range images). Numerical calculations have quantified the expected performance for both radio science and mm-VLBI applications as a function of elevation angle and WVR beamwidth. A beamwidth, full width at half maximum (FWHM), of 2 deg would allow useful calibration capability. However, FWHM … 1 deg is needed for optimum performance.
Keywords
Details
- Volume
- 42-145
- Published
- May 15, 2001
- Pages
- 1–13
- File Size
- 176.4 KB