Engineering topics
Publications and source records attributed to Hardi, D. E..
On May 23, 1996, Galileo successfully switched to a new telecommunication mode with upgraded software on the spacecraft and comprehensively revised ground equipment. The new link offers multiple techniques (arraying, error-correcting coding, data compression, etc) to maximize the data return, while applying automation to minimize the complexity and cost of operations.
After the Galileo High Gain Antenna (HGA) failed to deploy in 1991, the Jet Propulsion Laboratory(JPL) faced the challenge of implementing a science-rich mission with a Low-Gain Antenna (LGA), at data rates that were almost four orders of magnitude less than originally planned.
On day of the year 062, 1994, a prototype of the Deep Space Communications Complex Galileo Telemetry subsystem successfully tracked and processed signals from the Galileo spacecraft, under fully suppressed-carrier modulation. The demonstration took place at Goldstone, employing the 70-m antenna and the 34-m high-efficiency antenna. This article presents the findings from that demonstration. Specific issues are the system performance in terms of signal-to-noise (SNR) degradation and the arraying gain. Validation of the test results is via symbol-error-rate measurement and the standard symbol SNR. The analysis is also extended to include characterization of the signal received from Galileo.