Improvement of the sensitivity of millimeter wave radio telescopes by synchronous tracking
Abstract
At millimeter waves, a so called dual-beam technique was used in radio source flux measurements to eliminate the effect of atmospheric fluctuations. In practice, when a radome covered telescopes is used, it is found that the deviation of measured values is still several times larger than the theoretical value determined by the system noise temperature. The fluctuations in the background noise from the surroundings of the telescope (e.g., through the radome frame) are the main reason for the increased deviation. Measurements indicated that the variations in the background are quite stable. A so called synchronous tracking method was introduced for eliminating the effect of the background. Experimental results are given showing that using this observing method a deviation close to the theoretical value can be obtained.
- Publication:
-
NASA STI/Recon Technical Report N
- Pub Date:
- 1978
- Bibcode:
- 1978STIN...8114935T
- Keywords:
-
- Atmospherics;
- Background Noise;
- Flux (Rate);
- Millimeter Waves;
- Radio Telescopes;
- Sensitivity;
- Optical Equipment;
- Signal To Noise Ratios;
- Astronomy