Phasing the antennas of the Very Large Array (VLA) for reception of telemetry from Voyager 2 at Neptune encounter

Details Phasing the antennas of the Very Large Array (VLA) for reception of telemetry from Voyager 2 at Neptune encounter Phasing the antennas of the Very Large Array (VLA) for reception of telemetry from Voyager 2 at Neptune encounter

Aug 1988

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1988tdar.nasa..257u&link_type=abstract

In its The Telecommunications and Data Acquisition Report p 257-273 (SEE N89-10186 01-32)

Physics

Phased Arrays, Radio Telemetry, Radio Telescopes, Satellite Antennas, Signal Reception, Very Large Array (Vla), Atmospheric Effects, Bit Error Rate, Phase Coherence, Real Time Operation, Signal To Noise Ratios, Transmission Loss, Troposphere, Voyager Project

Scientific paper

The Very Large Array (VLA) radio telescope is being instrumented at 8.4 GHz to receive telemetry from Voyager 2 during its encounter with Neptune in 1989. The procedure in which the 27 antennas have their phases adjusted in near real time so that the signals from the individual elements of the array can be added coherently is examined. Calculations of the expected signal to noise ratio, tests of the autophasing process at the VLA, and off-line simulations of that process are all presented. Various possible procedures for adjusting the phases are considered. It is shown that the signal to noise ratio at the VLA is adequate for summing the signals from the individual antennas with less than 0.1 dB of loss caused by imperfect coherence among the antennas. Tropospheric variations during the summer of 1989 could cause enough loss of coherence to make the losses higher than 0.1 dB. Experiments show that the losses caused by the troposphere can probably be kept below 0.2 dB if the time delay inherent in the phase adjustment process is no longer than approx. 5 secs. This relatively small combining loss meets the goal estabished to minimize the bit error rate in the Voyager telemetry and implies adequate autophasing of the VLA.

Affiliated with

Also associated with

No associations

Rating

Phasing the antennas of the Very Large Array (VLA) for reception of telemetry from Voyager 2 at Neptune encounter does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Phasing the antennas of the Very Large Array (VLA) for reception of telemetry from Voyager 2 at Neptune encounter, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Phasing the antennas of the Very Large Array (VLA) for reception of telemetry from Voyager 2 at Neptune encounter will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1696704