Citation
Abstract
This article documents the results of experiments designed to verify the gravitycompensation and tracking performance of a novel seven-channel 32-GHz (Ka-band) array feed compensation system (AFCS) for the DSN’s 70-m antennas. The AFCS (along with other proposed compensation systems) was installed on the spare holography cone that was placed temporarily on the 70-m antenna in place of the X-band K-band radar (XKR) cone, which has been removed for repairs. These experiments took place from November 1998 through February 1999 and consisted of both quasar and spacecraft observations. Compensation performance was characterized in terms of both antenna-efficiency improvement and total signal-to-noise ratio (SNR) gain, while simultaneous-tracking capability was demonstrated by means of a least-squares tracking algorithm. A combined system consisting of the AFCS together with a deformable flat plate (DFP), designed to refocus divergent rays back in the array, also was examined briefly at low elevations. The results indicate that a properly designed real-time compensation system regains most of the SNR lost to deformations at low elevations and has the potential for similar improvements at high elevations, although this remains to be demonstrated.
Keywords
Details
- Volume
- 42-139
- Published
- November 15, 1999
- Pages
- 1–17
- File Size
- 676.8 KB