Citation
Abstract
The signal combiner performs the phasing and summing of a high data rate spacecraft telemetry signal received simultaneously at three DSN stations. The signals are combined at the subcarrier level after they have been microwaved to a common site. Before summing the signals the combiner delays them by the amount necessary to compensate for differences in phase due to unequal stationto-spacecraft distances and microwave delays. A tracking loop continuously adjusts for changes in signal delay so that correct phasing is automatically maintained throughout the spacecraft pass. The signal combiner was successfully used in an experiment designed to improve the quality of real-time video data of the Mariner 10 spacecraft at its second Mercury encounter. Two 26-m antenna stations were arrayed with one 64-m antenna station at the Goldstone Deep Space Communications Complex. This combination produced an improvement in signal-to-noise ratio of 0.8 dB when compared to the 64-m antenna station by itself.
Details
- Volume
- 42-25
- Published
- February 15, 1975
- Pages
- 111–117
- File Size
- 1.1 MB