Britannica
Sources used in this answer
What advantages does the Green Bank Telescope gain from its off-axis design?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
Radio telescope
Lovell Telescope, a fully steerable radio telescope at Jodrell Bank, Macclesfield, Cheshire, England.
The Robert C. Byrd Green Bank Telescope (GBT) utilizes an off-axis design to significantly improve the quality of its observations. By employing an off-axis support structure for the secondary reflector, the telescope effectively minimizes two primary sources of signal degradation:
- Ground Radiation: It reduces the amount of unwanted radiation picked up from the ground.
- Unwanted Reflections: It eliminates interference caused by reflections from the support legs that would otherwise obstruct the aperture.1
This design choice, combined with its computer-controlled surface panels, allows the GBT to operate with high precision at wavelengths as short as a few millimetres.1