Citation
Abstract
Models that show the effects of weather on noise temperature and attenuation of deep space telemetry signals received by the Deep Space Network (DSN) at Ka- and X-band (32 GHz and 8.5 GHz) are developed. These models have been used to compare the performance of telemetry links at these two frequencies. The models build on an earlier 1982 model that used three months of water vapor radiometer measurements (31.4 GHz) at Goldstone, augmented with one year of radiosonde measurements made at Edwards Air Force Base. This 1986 model accounts for annual variations of rainfall and extends to a model for Canberra, Australia, and Madrid, Spain. The results show, for example, that at Ka-band, 30-degree elevation angle, Goldstone weather adds less than 23 + 2 K to the system temperature 80% of the time, while Canberra or Madrid weather adds less than 32 + 5 K 80% of the time. At X-band, the comparable numbers are 5.1 + 0.2 K and 5.7 + 0.4 K. A simple analysis shows a substantial telemetry system signal-to-noise ratio advantage when operating at Ka-band compared to X-band.
Details
- Volume
- 42-88
- Published
- February 15, 1987
- Pages
- 135–140
- File Size
- 501.5 KB