Citation
Abstract
The technique of station arraying is used to improve the signal-to-noise ratio by reinforcing the coherent spacecraft signal while cancelling out location-dependent incoherent noise. The signal combiner provides a delay compensation that keeps the signals correctly phased throughout the spacecraft pass. The signals are combined to optimize the signal-to-noise ratio of the sum. The combined signal is then processed in the normal manner by the rest of the telemetry chain. During the Voyager Mission each Deep Space Station used its 64-meter antenna together with a 34-meter antenna to form an array. Data were selected from the Saturn encounter period from November 2 to November 13, 1980, to analyze the signal combiner performance. A statistical analysis of the residual gain data from all of the arrayed Deep Space Stations indicates that the Real-Time Combiner is operating within the designed accuracy range of 0.2 ±0.05 dB around the theoretical gain. A decrease in the residual gain value appears to correlate with an increase in antenna elevation, which may be directly related to the changing antenna gain with elevation. Overall, the combined signal-to-noise ratio is improved by an average of 0.62 ±0.15 dB over the 64-meter signal-to-noise ratio alone.
Details
- Volume
- 42-63
- Published
- June 15, 1981
- Pages
- 191–202
- File Size
- 701.9 KB