Home // SPACOMM 2012, The Fourth International Conference on Advances in Satellite and Space Communications // View article

Assessment of Weather Effects on DSN Antenna Tracking at Ka-band

Authors:
Timothy Pham

Keywords: Deep Space Network, Ka-band tracking, weather effect, antenna pointing, performance analysis

Abstract:
This paper presents the findings of weather statistics at the three sites of the NASA Deep Space Network(DSN) and the effect of weather on antenna tracking performance at Ka-band frequency, based on operational data. Both aspects of weather effects are examined: the distribution statistics of wind patterns and the antenna pointing performance (and hence received signal level) in the presence of high winds. Due to smaller beamwidth inherent in the large aperture of DSN antennas (34-m diameter for Ka-band reception), a small offset in antenna pointing caused by winds could significantly reduce the received signal power and potentially result in a data outage. Some past models indicated a strong wind impact. Winds, even at a moderately low speed of 16 km/hr (10 mph), can distort the antenna’s main reflector and cause signal degradation by as much as 2.9 dB at Ka-band frequency. Establishing the actual performance that is based on operational data is very important for mission operation planning, especially for missions that are power-constrained and thus need to conserve the link margin. Finding an optimal link margin setting that is neither wasteful nor insufficient would enable maximum data return for missions. The findings presented in this paper show that there are significant differences in the weather among the three DSN sites; thus, one possible strategy to maximize data return is to allocate more tracking at sites with low winds. Another surprising finding is that the wind effect is not as large as previously thought. Only small signal degradation (0.8 dB) was observed for wind speeds up to 50 km/hr.

Pages: 12 to 15

Copyright: Copyright (c) IARIA, 2012

Publication date: April 29, 2012

Published in: conference

ISSN: 2308-4480

ISBN: 978-1-61208-194-6

Location: Chamonix, France

Dates: from April 29, 2012 to May 4, 2012