The calibration of 20 and 30 GHz radiometers by using the ATS-6 satellite beacons
Abstract
The 20 and 30 GHz ATS-6 transmissions received by the British Post Office 6.1 m diameter aerial at Martlesham Heath, were used to calibrate co-located, small aperture (0.6 m diameter) radiometers directed along the ATS-6 22.7 deg elevated slant-path. The correlation method used to establish the calibration is described and the effects of system instabilities and atmospheric scintillation on the calibration are discussed in detail. It is shown that the calibrated radiometers can be used to predict slant-path attenuations for individual events of up to 13 db at 30 GHz and 9 db (the maximum value recorded) at 20 GHz within uncertainty limits of + or - 1.0 db. Cumulative distributions of predicted and directly measured attenuation for over 1000 hours of concurrent measurements show similar agreement. Finally, monthly and yearly cumulative distributions of slant-path attenuation predicted from over 6000 hours of radiometer data collected between August 1975 and July 1976 are presented.
- Publication:
-
ATS-6 Propagation Expts. in Europe
- Pub Date:
- October 1977
- Bibcode:
- 1977apee.rept..135B
- Keywords:
-
- Ats 6;
- Calibrating;
- Microwave Radiometers;
- Spacecraft Communication;
- Superhigh Frequencies;
- Antenna Radiation Patterns;
- Data Links;
- Microwave Attenuation;
- Noise Temperature;
- Radio Beacons;
- Scatterometers;
- Communications and Radar