Citation
Abstract
In this article, three new approaches to evaluating the performance advantage of the 32-GHz (Ka-band) frequency over the 8.4-GHz (X-band) frequency for receiving spacecraft downlink from deep-space missions are ofiered. For a given elevation profile for a pass, these approaches use atmospheric noise temperature statistics to select either the optimum data rate or the optimum data rate profile that maximizes the total data-return volume over the pass. For illustration purposes, these approaches are used to optimize the performance of a link for both X-band and Ka-band at Deep Space Network (DSN) 34-m beam-waveguide tracking stations at both Madrid, Spain, and Goldstone, California. Calculations show that by using these approaches an optimized Ka-band link, depending on the pass and the optimization method, ofiers between 4.7 dB and 7.2 dB more data volume than an optimized X-band link and between 7.0 dB and 10.9 dB more than an X-band link as currently operated by the DSN. These approaches provide performance gains in terms of average data return at the cost of reliability of the link or reduced tracking time or both. The reduced reliability of the link can have adverse efiects in the continuity of the data returned, which in turn can make the link performance unacceptable.
Details
- Volume
- 42-148
- Published
- February 15, 2002
- Pages
- 1–20
- File Size
- 332.7 KB